Multiple choice

A student goes to school on his Honda Activa. If he drives 5 kmph faster, he reaches 30 minutes early. If he drives 3 kmph slower, he reaches 30 minutes late. The distance (in km) is

  1. 15

  2. 20

  3. 25

  4. 30

  5. Cannot be determined
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let d be distance and v be speed. d/v - d/(v+5) = 0.5 and d/(v-3) - d/v = 0.5. Solving these equations: d/v - d/(v+5) = d/(v-3) - d/v. 2/v = 1/(v-3) + 1/(v+5). Solving for v gives v = 15. Then d = 30.

Keep practicing — related questions