Multiple choice

Shivam alone can complete a piece of work in 10 days and Satyam alone can complete the same work in 40 days. If they work on alternate days with Shivam starting the work, then in how many days will the work be completed?

  1. 12

  2. 15

  3. 20

  4. 16
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Shivam's 1-day work = 1/10, Satyam's = 1/40. In 2 days, they complete 1/10 + 1/40 = 5/40 = 1/8. After 14 days (7 pairs), 7 × 1/8 = 7/8 done. Day 15: Shivam does 1/10, total 7/8 + 1/10 = 35/40 + 4/40 = 39/40. Day 16: Satyam does 1/40, total = 40/40 = 1 (complete).

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