Term
| Betty and Tracy planned a 5000km trip in an automobile with five tires, of which four are in use at any time. They plan to interchange them so that each tire is used the same number of kilometers. What is the number of kilometers each tire will be used? |
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Definition
5 tires 5000kms
4 at each time
4 * 5000km = 20,000km travelled by 4 tires.
20,000/5 = 4000km each |
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Term
| It takes 4 1/2 minutes for Elton John to listen to his favorite song on a record recorded at 45 r.p.m. (revolutions per minute). One day, Elton accidentally played this record at 33 1/3 r.p.m.'s. What was the number of revolutions required to play the song? What was the amount of time it took to play it at 33 1/3 r.p.m.? |
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Definition
4.5 min 45r/min = 202.5 revolutions
202.5rev/33.3 r/m = 6.075 minutes. |
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Term
| Allie has an income which is five eighths that of Basil. Allie's expenses are one-half those of Basil and Allie saved 40% of his income. What is the percentage of his income that Basil saves? |
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Definition
A_i=5/8*B_i A_e=1/2*B_e
0.4*(5/8*B_i)=5/8*B_i - 1/2**B_e
0.375*B_i=1/2*B_i
B_e=0.75B_i
Therefore Basil saves 25% of his income.
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Term
| Todd and his brother have each agreed to mow half of the front lawn, which is a 20m by 40m rectangle. The mower cuts a 1m wide strip. If Todd starts at the corner and mows around the lawn toward the center, about how many times around must he go before he has mowed his half? |
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Definition
Area = 800m
2
Todd must mow 400m
2
length and width reduce by 2m
Time around the lawn Area remaining
start 20*40=800 m
2
1 time 18*38=684 m
2
2 times 16*36=576 m
2
3 times 14*34=476 m
2
4 times 12*32=384 m
2
About 3 and 1/2 times he would have to go around the lawn to
do his share!! |
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Term
| A dog chasing a rabbit, which has a start of 45m, jumps 3m every time the rabbit jumps 2m. In how many leaps does the dog overtake the rabbit? |
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Definition
Let x = the number of jumps taken
3x = 45 + 2x
x=45
45 jumps he will have caught up with the rabbit |
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