Question

Brenda and Sally run in opposite directions on a circular track, starting at diametrically opposite points. They first meet after Brenda has run $100$ meters. They next meet after Sally has run $150$ meters past their first meeting point. Each girl runs at a constant speed. What is the length of the track in meters?

$250$

$300$

$350$

$400$

$500$

Answer: C

Concepts:relative speed distance rate and time ratio and proportion

Difficulty rating: 1540

Solution:

Before the first meeting the two together cover half the track. Between the first and second meetings they together cover a full track, which is twice as far, so Brenda runs $2 \cdot 100 = 200$ meters in that stretch.

Sally runs $150$ meters in the same stretch, so the full track length is $200 + 150 = 350.$

Thus, the correct answer is C.

2004 AMC 10A Problem 17

Answer: C

Difficulty rating: 1540

Solution:

Problem 17 in Other Years