AMC 10 Weekly Practice Round 2

Complete problem set with solutions and individual problem pages

Problem 16 Easy

Place A and Place B were 71 \text{km} apart. Calvin and Yvonne departed from the two places respectively and travelled towards each other. Calvin started his journey 20 minutes later than Yvonne, but he travelled faster than Yvonne by 3 \text{km}/\text{h}. The two of them came across each other two hours after Calvin's departure from Place A. Calvin travelled at(   )\text{km}/\text{h}.

  • A.

    15

  • B.

    16

  • C.

    17

  • D.

    18

  • E.

    19

Answer:D

Let A travel at x km per hour, and B travel at \left( x - 3 \right) km per hour.

2x + \frac{7}{3} \left( x - 3 \right) = 71

Solving gives: x = 18.

\therefore A travels at 18 km per hour.