March
Puzzlers don't puzzle YSL.com viewers
Mr. Math Puzzler's
March questions had a lot of illustrations. But, a bunch of
you saw right through them and found correct answers.
Ten YSL.com
viewers answered all six of the Math Puzzlers correctly. The
winners included a number who hadn't entered before. That's
good. We want the Puzzlers to provide fun for kids throughout
the St. Louis metro area.
The ten who answered
all of the questions correctly were:
Clayton Vance
of Mason Ridge Elementary, Courtney Lauer of Green Park Lutheran,
Drew Fendler of Sperreng Middle and Phillip Hsu of Wild Horse
Elementary plus three winners from Immaculate Conception at
Old Monroe and three from St. Gabriel Catholic.
The Immaculate
Conception winners were Tim Hekenewerth, Steven Price and
Leah Vandiver.
Winners from St.
Gabriel were Amy Lange, Lauren Kloeppinger and one girl who
didn't want her name listed.
Since we had so
many winners, we had a drawing to see which kids won the $10
Borders book certificates. When there are more than three
winners, we put the winning entries in a hat and draw out
three names to get the awards.
The certificate
winners were Clayton Vance, Drew Fendler and Phillip Hsu.
Congratulations
to all those who answered the six March Puzzlers correctly.
Remember, all
kids ages 8 to 13 in the St. Louis metro area can enter this
Math Puzzler competition.
Although you wouldn't
know it from the number of winners this month, the Puzzlers
can be difficult. That's especially true for the younger kids.
But, YSL.com
doesn't mind if you get some help from your parents or older
brothers and sisters. You might like to make this a family
activity each month. Or you could get some friends together,
figure the answers and then each submit an entry.
To enter the April
competition, just click here
for the new Puzzlers.
Answers
for March Math Puzzlers
1. The five numbers
within each circle represent a mathematical relationship.
This same relationship is displayed in each of the four circles.
Following this relationship, what number does the question
mark in Circle 4 represent?
Answer:
3
Explanation:
The common relationship of the circles is that if the product
of the vertical numbers is divided by the product of the horizontal
numbers, the answer will be the number in the little circle.
Thus, in the fourth circle, 2 x 6 = 12 and is divided by 4
(1 x 4) to get 3.
2. After dinner,
cookies were served for dessert. Ann took one fourth of the
cookies. Betty took one third of what remained. Calvin took
one half of what was left. And Dillon received the remaining
six cookies. How many cookies did each child get? (Hint:
We've done a Puzzler similar to this before.)
Answer:
6 cookies each
Explanation:
Ann gets 1/4th of the cookies; Betty gets 1/3rd of the remainder
(which turns out to be 1/4th of all the cookies). Calvin gets
1/2 of what's left (which turns out to be 1/4th of the total
also.) Then Dillon gets six cookies.
The formula:
1/4C
+ 1/4C + 1/4C + 6 = C
3/4C
+ 6 = C
-3/4C =
-3/4C
-------------
4(6)
= 4(1/4C)
24
= C
with
each getting 6 cookies.
3. Using the dart
board below, how could you get exactly 100 points using just
five darts?
Answer:
Two 23s, one each 9, 17 and 28
Explanation:
This answer needs to be found with educated guessing. You
needed to try different combinations until you find the five
numbers that add up to 100.
4. A student lives
in each home marked A, B, C and D. Each student goes to a
different school. The student in House A goes to School A,
House B to School B, etc. Find a path for each student to
give his/her own school without crossing the paths of any
of the other students.
Answer:
Use lines on the illustration
Diagrammed
explanation: Those who answered this question correctly found
a number of different paths to the schools that didn't cross
any other paths.
5. A worker left
two planks leaning against each other between two buildings
as show below. One plant is 8 feet long and the other is 6
feet long. The buildings are 10 feet apart. How high is Point
A above the ground?
Answer:
4.8 feet
Explanation:
This is a multi-stage problem. The key to this answer is proving
that one of the angles in the triangle is a 90 degree angle.
That can be done by using the Pythagorean Theorem to find
enough information. If one of those angles hadn't been a right-angle,
there wouldn't be enough information given.
First, you
need to find the area of the large triangle with the formula
of
Base
x Height
Area = -------------
2
6 x 8
A = -----
2
A = 24
Knowing the
area of the triangle is 24, we can use the 10-foot leg as
the base and work backwards to find the height.
A
= B x H
-----
2
24
= 10H
2(10H)
2(24) = ------
2
48 10H
-- =
---
10 10
4.8
= H
6. As I approached
an elevator in an office building. I noticed a sign on the
wall. It said the capacity of the elevator was 2,160 pounds.
It continued to say that meant either 9 women or 6 men, or
6 women and 8 men. What weight was presumed for each woman
and each man?
Answer:
women, 120 lbs; men 180 lbs.
Explanation:
The answer comes by using the system of linear equations.
You need two equations. One is: 9W + 6M = 2,160 pounds; the
other is 6W + 8M = 2,160 pounds
Next, we need
to get rid of the women to focus the attention on the weight
of the men (You also could work the formula to get rid of
the men and get the women's weight first):
-2(9W
+ 6M = 2,160) --> -18W - 12M = -4,320
3(6W + 8M = 2,160) --> 18W
+ 24M = 6,480
-------------------
12M
= 2,160
M = 180
Then, using
one of the ratios in the question, 8 men would weigh or 1,440
pounds. Then, the six women would weight the difference between
2,160 and 1,440 or 720 pounds. Then, each woman weights 120
pounds.
