| Problem |
Hint |
1) It takes 4 workers 5 hours to build 6 structures. At this rate, how long will it take 2 workers to
build 9 structures?
|
- Time to accomplish 1 job: Compute the total number of hours to do 1 job as the number of workers times the number of hours worked divided by the number of structures built.
T = _____________
- Time to accomplish N jobs: Multiply this by 9 to get the total number of hours to accomplish 9 structures
TN = ___________
- Time to accomplish N jobs with W workers:
Divide this by the number of workers = _______ hours
|
2) A coat is priced at $155. In January, the style seems popular so the store raises the price by 20%.
Unfortunately, the coat does not sell at that price. In April, the price is reduced by 20%. What is the
price of the coat after this?
|
A price raise of 20% is a multiply of the original price by 1.2
A price reduction of 20% is a multiply of the original price by
(1 - 0.2) = 0.8
- Coat price after price raise = ________
- Coat price after 20% reduction of the above price after increase
(not from the original price) = _______
|
3) A rectangular box has a surface area of 94 square inches and a volume of 60 cubic inches. A new box is made that is a scaled up version of this original box. The new box has a surface area of 376 square inches. What is the volume of the new box?
|
- Assume the box is a cube (this makes the computation easier). Compute the length of a side as the square root of the total surface area / 6
(because there are 6 sides) :
s = ______ in.
- Compute the length of a side of the larger cube :
s = _______ in.
- Compute the ratio of these side lengths and cube it = ______
- Multiply the original volume by this ratio:
new volume = ________ cu. in.
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