WBCS.LIVE practice question

If A can do a piece of work in 10 days and B can do the same work in 15 days, how many days will they take to complete the work together?

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

Answer options

  1. 5 days
  2. 9 days
  3. 8 days
  4. 6 days

Correct answer and explanation

Correct answer: 6 days

Explanation: ✅ Correct Answer: (D) 6 days 📚 Explanation: Step-1: Calculate the 1-day work of A and B. A's 1-day work = 1÷10 and B's 1-day work = 1÷15. Step-2: Add their 1-day work together: (1÷10 + 1÷15). The LCM of 10 and 15 is 30. So, (3+2)÷30 = 5÷30 = 1÷6. Step-3: Since their combined 1-day work is 1÷6, they will take 6 days to finish the work together.