Multiple choice

The ratio of the efficiencies of A, B and C is 7 : 5 : 4. By working together, they can finish a work in 35 days. A and B work together for 28 days. The remaining work completed (in days) by C alone will be

  1. 56

  2. 63

  3. 49

  4. 60
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Total work = (7+5+4) * 35 = 16 * 35 = 560 units. A+B work for 28 days: (7+5) * 28 = 12 * 28 = 336 units. Remaining work = 560 - 336 = 224 units. C's efficiency = 4. Days for C = 224 / 4 = 56.

AI explanation

Taking the total work as the product of the total efficiency sum (16) and the days (35), the total work is 560 units. The combined daily work of A and B is 12 units, so in 28 days they complete 336 units, leaving 224 units of work. Since C's daily work is 4 units, C will take 56 days (224 divided by 4) to complete the remaining work.

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