Multiple choice general knowledge math & puzzles

A boat goes 45 km. up stream in 9 hours and a distance of 49 km. downstream in 7 hours. The speed of the boat in still water is:

  1. 5 km/hr

  2. 6 km/hr

  3. 5.5 km/hr

  4. 6.5 km/hr

  5. 7 km/hr

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Upstream speed = 45/9 = 5 km/hr. Downstream speed = 49/7 = 7 km/hr. Speed in still water = (Downstream + Upstream) / 2 = (7 + 5) / 2 = 6 km/hr.