Multiple choice general knowledge math & puzzles

A ball is dropped from a height of 120 m, and bounces back to 5/6 of previous height every time. Calculate total distance travelled by the ball till it becomes stationary..

  1. 1340 m

  2. 1360 m

  3. 1320 m

  4. 1380 m

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

The ball drops 120 m down, then bounces back up to 100 m (5/6 of 120), down again 100 m, up to 83.33 m (5/6 of 100), continuing this geometric pattern. Total distance = 120 + 2×100 + 2×83.33 + 2×69.44 + ... = 120 + 2×120(5/6 + 25/36 + 125/216 + ...) = 120 + 2×120 × (5/6)/(1-5/6) = 120 + 2×120×5 = 1320 m.