Multiple choice

Two men A and B can complete a piece of work in 10 days and 15 days respectively.They started the work together but A left after 3 days and another person C joins the who can complete the work in 30 days. In how many days the work got completed ?

  1. 6 days

  2. 7days

  3. 10 days

  4. 8 days

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

A and B together complete 1/10 + 1/15 = 1/6 of the work daily. In 3 days, they finish 3/6 = 1/2 of the work. The remaining 1/2 is completed by B and C working together at 1/15 + 1/30 = 1/10 per day, taking 5 more days. Total time = 3 + 5 = 8 days.