| Problem |
Solution |
|
1) Guess this number from the clues:
The least common multiple of this number and 42 is 630.
The greatest common factor of this number and 42 is 6. |
- Use the GCF-LCM equation:
The LCM of 2 numbers is their multiple divided by their GCF:
LCM(A,B) = A x B / GCF(A,B)
Let A be the other number.
B = 42
- Solve this for A
630 = 42 A / 6
42A = 3280
A = 90
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2) A food stand buys ice cream cones in packages of 8. Each carton of ice cream will make 12
cones. What is the least number of packages of ice cream cones and cartons of ice cream that need
to be bought to have no leftover ice cream and no leftover cones? |
This is a least common multiple problem.
1. The LCM of 2 numbers is their multiple divided by their GCF:
LCM(A,B) = A x B / GCF(A,B)
2. What is the LCM of 8 and 12? LCM(8,12) = 96/4 = 24
3. Divide this by the number of ice cream cones in a package = 24/8 =
3 packages of ice cream cones
4. Divide this by the number of cones that a carton makes = 24/12 =
2 cartons of ice cream.
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3) Eddie has saved $1,200 which is 32% of the price of a used car that he wants to buy. What is the
price of the car? |
1. Write an equation for "$1200 = 32% of X", and solve,
.32 X = $1200
X = $1200 / .32 = $3750
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5) In the diagram the sum