WBCS.LIVE practice question

A can do a piece of work in 20 days, and B can do the same in 30 days. They started the work together, but A abandoned the work 5 days before its completion. How many days did the total work last?

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. 12 days
  2. 14 days
  3. 15 days
  4. 16 days

Correct answer and explanation

Correct answer: 15 days

Explanation: āœ… Correct Answer: C) 15 days šŸ“š Explanation: Let the total work be 60 units (LCM of 20 and 30). A's efficiency is 3 units/day, and B's is 2 units/day. Let the total work last for 'x' days. Since A left 5 days early, A worked for (x - 5) days, while B worked for the full 'x' days. Equation: 3(x - 5) + 2x = 60. This gives 3x - 15 + 2x = 60, meaning 5x = 75. Therefore, x = 15 days.