Subj:
Math4  Supplement 2
(Includes 21 jokes and articles, 13 1031,8,cf,vXT4,5) 

Fractal from
Best Animation

Includes the following: MATH
PROB.  Simple Algebra Question (DU)
.........................MATH
PROB.  The Gold Chain (S458b, S637)
.........................MATH
PROB.  String On The Cylinder (S458)
.........................MATH
PROB.  The Rectangle At The Corner (S456)
.........................MATH
PROB.  The Sum Of Real Numbers (S455)
.........................MATH
PROB.  21 Factorial (S455b)
.........................MATH
PROB.  Winding Vine Length (S454b)
.........................MATH
PROB.  Two Ladders (S453b)
.........................MATH
PROB.  Ant On A Box (S453)
.........................MATH
PROB.  27 Cubes (S452)
.........................MATH
PROB.  The Anchor (S452b)
.........................MATH
PROB.  4 Trees (S451)
.........................MATH
PROB.  Analog Clock Problem 1 (S448b)
.........................MATH
PROB.  Five Hats (S448b)
.........................MATH
PROB.  Train Bridge (S447b)
.........................Math
Prob.  Finding The Counterfeit Coin (S439b)
.........................Math
Prob.  Figure this Pattern (S347b)
.........................LOGIC
PROB.  Beanstalk
.........................LOGIC
PROB.  Dog, Chicken, And Rice At River (S454)
.........................PUZZLE
 Square Division (S457)
.........................PUZZLE
 Adjacency Grid (S456b)
.........................PUZZLE
 Chess Puzzle I (S449 in gamessupp)
.........................PUZZLE
 9 Dots And 4 Lines (S448)
The MATH1
file are nonmathematical math jokes
MATH2
file are mathematical jokes
Math3
file contains tests, and formulas
Math4
file contains problems
Math5
file contains quotes
MATH6
file contains lymerics, short jokes, stories, and QA.
To see other type puzzles go to the
following:
Bottle Caps  (See
whole file)
BRAIN TEASERS (See whole
file)
ILLUSIONS  (See
whole file)
Riddles file  (See whole file)
WORD PUZZLES  (See whole
file)
TEST FACES  (See
whole file)
============================================================Top
Subj: MATH
PROB.  Simple Algebra Question (DU)
From: Dawn Macie on Facebook on 10/13/2016
Source: https://onsizzle.com/i/thissimplealgebraques
.........tionisconfusingtheinternetcanyou2741544
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Top
Subj:
MATH PROB.  The Gold Chain (S458b, S637)
From: Gray's Brain Teasers on 10/30/05
Source: (Removed from 256.com/gray/teasers) 

A woman wants to buy a painting
at an auction where you bid
grams of gold instead of money.
She owns a gold chain made
of 23 interlocking loops, each
weighing 1 gram. She wants
to go to a jeweler before the
auction to cut the minimum
number of loops that would allow
her to pay any sum from 1
to 23. For example, she
could pay a 13 gram price with a
12 link chain and a single link.
After much thought, she
figures out a way to do it by
cutting just 2 of the loops
in the chain. How many
loops are in the pieces of chains
that she has after the 2 cuts?
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To see the solution
click 

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Top
Subj: MATH
PROB.  String On The Cylinder (S458)
From: Puzzles And Brain Teasers 10/29/2005
At: http://www.syvum.com/cgi/online/serve.cgi
...../contrib/teasers/string1.tdf?0


A cylinder 72 cm high
has a circumference of
16 cm. A string makes exactly
6 complete
turns round the cylinder while its
two ends
touch the cylinder's top and bottom.
How long is the string in cm? 
Top
Subj: MATH
PROB.  The Rectangle At The Corner (S456)
From: Puzzles and Brain Teasers on 10/20/2005
At: http://www.syvum.com/cgi/online/serve.cgi
...../contrib/teasers/rectang1.tdf?0

In the left figure, the
rectangle at
the corner measures 3 cm x 6 cm.
What is the radius of the circle in
cm?

Top
Subj: MATH
PROB.  The Sum Of Real Numbers (S455)
From: William Wu of U. C. Berkeley on 8/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#sumOfRealNumbers
The sum of N real numbers (not
necessarily unique) is 20.
The sum of the 3 smallest of
these numbers is 5. The sum
of the 3 largest is 7. What
is N?
Top
Subj: MATH
PROB.  21 Factorial (S455b)
From: William Wu of U. C. Berkeley on 8/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#21factorial
21!=510909x21y1709440000
Without calculating 21!, what
are the digits marked x and y?
Top
Subj: MATH
PROB.  Winding Vine Length (S454b)
From: William Wu of U. C. Berkeley on 8/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#windingVineLength
There is a tree 20 feet high,
with a circumference of 3 feet.
A vine starts at the base of
the tree and winds around the
tree 7 times before reaching
the top. How long is the vine?
Hint: There is an easy way to
solve this problem which only
uses junior high school math
Top
Subj: MATH
PROB.  Two Ladders (S453b)
From: William Wu of U. C. Berkeley on 8/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#twoLadders
Two ladders are placed crosswise
in an alley to form a
lopsided Xshape. Both
walls of the alley are perpendicular
to the ground. The top
of the longer ladder touches the
alley wall 5 feet higher than
the top of the shorter ladder
touches the opposite wall, which
in turn is 4 feet higher
than the intersection of the
two ladders. How high above
the ground is that intersection?
Top
Subj: MATH
PROB.  Ant On A Box (S453)
From: William Wu of U. C. Berkeley on 8/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#antOnABox
A 12 by 25 by 36 inch box is
lying on the floor on one of
its 25 by 36 inch faces.
An ant, located at one of the
bottom corners of the box, must
crawl along the outside of
the box to reach the opposite
bottom corner. It can walk
on any of the box faces except
for the bottom face, which
is in flush contact with the
floor. What is the length of
the shortest such path?
Top
Subj: MATH
PROB.  27 Cubes (S452)
From: William Wu of U. C. Berkeley on 8/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#27cubes
A cube is to be cut into 27 smaller
cubes (just like a
Rubik's Cube). It is clear
that this can be done with
6 cuts to the original cube
(2 in the x, 2 in the y, 2
in the z). Now, assuming
that you can arrange the pieces
however you like before doing
a cut, what is the minimum
number of cuts required to obtain
the 27 smaller cubes?
Top
Subj: MATH
PROB.  The Anchor (S452b)
From: William Wu of U. C. Berkeley on 8/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#anchor
A boat of mass M1 is floating
in a lake of water. The
volume of the lake is V.
The water surface is initially
at height h, as measured relative
to the lake's floor.
There is an anchor of mass M2
sitting on the boat's deck.
A person standing on deck picks
up the anchor and throws
it overboard. The anchor
then sinks to the bottom of the
lake, and the water surface
height becomes h'.
Which of the following qualitiative
relationships is
correct? What assumptions
are you making about the
values of M1, M2, h, and V?
1. h' ? h
2. h' = h
3. h' > h
Note: From the US Navy's nuclear
power program interview
for naval officers!
Top
Subj: MATH
PROB.  4 Trees (S451)
From: William Wu of U. C. Berkeley on 8/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#placingTrees
You are a landscape specialist,
and have been asked to
design a garden for a math professor.
He wants four trees
that are all equidistant from
each other. How do you place
the trees?
Top
Subj: MATH
PROB.  Analog Clock Problem 1 (S448b)
From: William Wu of U. C. Berkeley on 8/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#analogClock1
An analog clock reads 3:15. What
is the angle between the
minute hand and hour hand?
Soultion backwards: seergedflahenodnaneves
Top
Subj: MATH
PROB.  Five Hats (S448b)
From: William Wu of U. C. Berkeley
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#3hats
There are 3 black hats and 2
white hats in a box. Three
men we will call them A, B,
? C) each reach into the box
and place one of the hats on
his own head. They cannot
see what color hat they have
chosen.
The men are situated in a way
that A can see the hats on
B and C's heads, B can only
see the hat on C's head and
C cannot see any hats.
When A is asked if he knows the
color of the hat he is wearing,
he says no. When B is
asked if he knows the color
of the hat he is wearing he
says no. When C is asked
if he knows the color of the
hat he is wearing he says yes
and he is correct. What
color hat and how can this be?
.
..........................
Top
Subj: MATH
PROB.  Train Bridge (S447b)
From: William Wu of U. C. Berkeley
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#trainBridge
A man is 3/8's of the way across
a train bridge, when he
hears the whistle of an approaching
train behind him. It
turns out that he can run in
either direction and just
barely make it off the bridge
before getting hit. If he
is running at 15 mph, how fast
is the train traveling?
Assume the train travels at
a constant speed, despite
seeing you on the tracks.


Note: From a 7th grade
prealgebra book. 
Top
Subj: Finding
The Counterfeit Coin (S439b)
..........From:
LABLaughsRiddles on 6/21/2005
You have 12 identicallooking
coins, one of which is
counterfeit. The counterfeit
coin is either heavier
or lighter than the rest.
The only scale you have to
use is a simple balance.
Using the scale only three
times (Note: not loading, but
using for balancing),
find the counterfeit coin.
x
x
x
x
x
Scroll down for the answer
x
x
x
x
x
Here it comes
x
x
x
x
x
Number the coins 1 through 12.
Weigh coins 1,2,3,4 against
coins 5,6,7,8. If they
balance, weigh coins 9 and 10 against
coins 11 and 8 (we know from
the first weighing that 8 is a
good coin). If they balance,
we know coin 12, the only
unweighed one is the counterfeit.
The third weighing
indicates whether it is heavy
or light.
If, however, at the second weighing,
coins 11 and 8 are
heavier than coins 9 and 10,
either 11 is heavy or 9 is light
or 10 is light. Weight
9 with 10. If they balance, 11 is
heavy. If they don't balance,
either 9 or 10 is light.
Now assume that at first weighing
the side with coins 5,6,7,8
is heavier than the side with
coins 1,2,3,4. This means that
either 1,2,3,4 is light or 5,6,7,8
is heavy. Weigh 1,2, and
5 against 3,6, and 9.
If they balance, it means that either
7 or 8 is heavy or 4 is light.
By weighing 7 and 8 we obtain
the answer, because if they
balance, then 4 has to be light.
If 7 and 8 do not balance, then
the heavier coin is the
counterfeit.
If when we weigh 1,2, and 5 against
3,6 and 9, the right side
is heavier, then either 6 is
heavy or 1 is light or 2 is light.
By weighing 1 against 2 the
solution is obtained.
If however, when we weigh 1,2,
and 5 against 3, 6 and 9, the
right side is lighter, then
either 3 is light or 5 is heavy.
By weighing 3 against a good
coin the solution is easily
arrived at.
Top
Subj: Math
Prob.  Figure this Pattern (S347b)
From: LABLaughsRiddles on 6/10/2005
Good at math? Try this one....
1=3
2=3
3=5
4=4
5=4
6=3
7=5
8=5
9=4
10=3
So what does
11=?
12=?
x
x
x
x
x
Scroll down for the answer
x
x
x
x
x
Here it comes
x
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x
x
11 equals six and twelve equals
six (the number of letters
in the numbers name
Top
Subj:
LOGIC PROB.  Beanstalk
From: Braingle.com
on 10/29/2005 (S458 in GamesSupp) 

Source: http://www.braingle.com/games/beans/index.php
This SWF game is a series of
pure logic puzzles to be
solved. It plays best
at the above source because you
can save levels, or you can
play it on my web site by
clicking 'HERE'.
Top
Subj: LOGIC
PROB.  Dog, Chicken, And Rice At River (S454)
From: William Wu of U. C. Berkeley on 8/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#dogChickenRice
A farmer returning home from
the market must get across the
river and return home with his
three purchases, a dog, a
chicken and a bag of rice.
However, He must take them in
his boat. He can't have
more than one item with him on his
boat at all times. He
cannot leave the dog alone with the
chicken because the dog will
eat the chicken, and he cannot
leave the chicken alone with
the bag of grain because the
chicken will eat the bag of
grain. How does he get all
three of his purchases back
home safely?
Top
Subj: PUZZLE
 Square Division (S457)
From: William Wu of U. C. Berkeley on 10/25/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/medium.shtml#squareDivision
Draw a square. Divide it
into four identical squares.
Remove the bottom left hand
square. Now divide the
resulting shape into four identical
shapes.
Top
Subj: PUZZLE
 Adjacency Grid (S456b)
From: William Wu of U. C. Berkeley on 10/24/2005
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/medium.shtml#adjacencyGrid
Arrange the numbers 1 to 8 in
the grid below such that adjacent
numbers are not in adjacent
boxes (horizontally, vertically, or
diagonally).
The arrangement above, for example,
is wrong because 3 and 4,
4 and 5, 6 and 7, and 7 and
8 are adjacent.
Top
Source: http://www.ocf.berkeley.edu/~wwu
........./riddles/easy.shtml#chessPuzzle1
Green numbers indicate how many
pieces could move to that
square on the next move.
Blue squares show the possible
locations of the following five
shown, different chess
pieces: How are the five
pieces arranged?
To try this chess puzzle by clicking
'HERE'.
Top
Subj: PUZZLE
 9 Dots And 4 Lines (S448)
From: William Wu of U. C. Berkeley
At: http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml
Source: http://www.ocf.berkeley.edu/~wwu/riddles/easy.shtml#9dots


You have 9 dots arranged
like a rectangle.
Without lifting your pen, or retracing
a
line, connect all nine dots with four
lines. 

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...............................From
LABLaughsRiddles 20040831
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