This GMAT Math practice question is from the topic rates: Concept covered is race between two runners.
- 10 meters
- 25 meters
- 45 meters
- 15 meters
- 35 meters
Explanatory AnswerVideo explanation will be added soon
A runs 25% as fast as B.
i.e., if B runs 100 m in a given time, A will run 125 m in the same time.
In other words, if A runs 5 m in a given time, then B will run 4 m in the same time.
Therefore, if the length of a race is 5 m, then A can give B a start of 1 m (A can allow B to start 1 ahead of the starting point) so that they finish the race in a dead heat.
Ratio of length of start given : length of race :: 1 : 5
In this question, we know that the start given is 7 m.
Hence, the length of the race will be 7 * 5 = 35 m.
Choice E is the correct answer.