Multiple choice

Rahul can complete a piece of work in 15 days, working 6 hours a day. Seema can complete the same work in 10 days, working 8 hours a day. If Rahul and Seema work together, working 6 hours a day, then in how many days can they complete the work?

  1. 6 1 17 days

  2. 7 1 17 days

  3. 5 1 17 days

  4. 6 days

  5. 9 days
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Rahul: 15 days * 6 hrs/day = 90 hours total. Seema: 10 days * 8 hrs/day = 80 hours total. Combined rate = 1/90 + 1/80 = (8+9)/720 = 17/720 work/hour. Working 6 hours/day, they do (17/720) * 6 = 17/120 work/day. Days = 120/17 = 7 and 1/17 days.

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