Multiple choice general knowledge math & puzzles

Ben can have a piece of work done in 8 days, Joe can work three times faster than the Ben, Ram can work five times faster than Ben. How many days will they take to do the work together ?

  1. 3 days

  2. 9/8 days

  3. 8/9 days

  4. 4 days

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

Ben's rate = 1/8 work per day. Joe is 3× faster: rate = 3/8 per day. Ram is 5× faster: rate = 5/8 per day. Combined rate = 1/8 + 3/8 + 5/8 = 9/8 work per day. Time = Work ÷ Rate = 1 ÷ (9/8) = 8/9 days. This is approximately 0.89 days or about 21.3 hours.