Multiple choice

'A' alone can complete a job in 10 days, while 'B' alone can complete it in 15 days. If A and B work together, in how many days will the job get completed?

  1. 9.5 days

  2. 7.5 days

  3. 6 days

  4. 5 days

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

Combined rate = 1/10 + 1/15 = 3/30 + 2/30 = 5/30 = 1/6. Time taken = 6 days.

AI explanation

Using the LCM method, let the total work be the least common multiple of 10 and 15, which is 30 units. The daily work done by A is 3 units and by B is 2 units. Working together, their combined daily work is 5 units, so the time required is 30 divided by 5, which equals 6 days.