Multiple choice

Vicky can do a job in 20 days, Ram in 30 days and Rahul in 60 days. If Vicky is helped by Ram and Rahul every 3rd day. How long will it take for them to complete the job?

  1. 18 days

  2. 15 days

  3. 12 days

  4. 10days
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Vicky's rate = 1/20, Ram = 1/30, Rahul = 1/60. Every 3rd day, work done = 3*(1/20) + (1/30 + 1/60) = 3/20 + 3/60 = 3/20 + 1/20 = 4/20 = 1/5. In 3 days, 1/5 of the job is done. Total time = 3 * 5 = 15 days.

AI explanation

Using the least common multiple method, let the total work be 60 units, making the daily work of Vicky, Ram and Rahul 3, 2 and 1 units respectively. Vicky works every day, while Ram and Rahul join him every third day, meaning their 3-day cycle work is 3+3+6 = 12 units. Completing five such cycles takes 15 days and accomplishes exactly 60 units of work. Therefore, the job is completely finished in 15 days.

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