Question

Jack and Jill are going swimming at a pool that is one mile from their house. They leave home simultaneously. Jill rides her bicycle to the pool at a constant speed of $10$ miles per hour. Jack walks to the pool at a constant speed of $4$ miles per hour. How many minutes before Jack does Jill arrive?

$5$

$6$

$8$

$9$

$10$

Answer: D

Concepts:distance rate and time

Difficulty rating: 660

Video solution:

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Written solution:

Jack travels at a rate of $4$ miles per $60$ minutes. Therefore, it takes him $\dfrac{60}{4} = 15$ minutes to get to the pool.

Jill travels at a rate of $10$ miles per $60$ minutes. Therefore it takes her $\dfrac{60}{10} = 6$ minutes to get to the pool.

Therefore, the difference in their times is $15-6 = 9$ minutes.

Thus, the correct answer is D .

2015 AMC 8 Problem 3

Answer: D

Difficulty rating: 660

Video solution:

Written solution:

Problem 3 in Other Years