Multiple choice

Mohan takes $16$ days less than Manoj to do a piece of work. If both working together can do it in $15$ days, in how many days will Mohan alone complete the work?

  1. $24\ days$
  2. $22\ days$
  3. $20\ days$
  4. $26\ days$
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A Correct answer
Explanation

Let Manoj take x days, Mohan takes x - 16 days. Together: 1/(x-16) + 1/x = 1/15. Solving this quadratic: x^2 - 46x + 240 = 0. Factors are (x-40)(x-6) = 0. Since x > 16, x = 40. Mohan = 40 - 16 = 24 days.

AI explanation

Let Manoj take x days, so Mohan takes (x - 16) days. Using the combined work formula, 15 times x plus 15 times (x - 16) equals x times (x - 16), which simplifies to x squared minus 46x plus 240 equals zero. Factoring gives x equal to 40 or 6, but x equal to 6 is invalid because x minus 16 would be negative. Manoj takes 40 days and Mohan takes 40 minus 16 days, resulting in 24 days.