21 men can do a piece of work in 35 days by working 9 hrs a day. But 15 women can do it in 27 days by working 7 hrs a day. Then the ratio of the work done by 1 man and 1 woman is:
Answer & explanation
Correct answer: option 4
Total Work = No. of person × days
Therefore,
Total work ⇒ 21M × 35 x 9 = 15W × 27 x 7
⇒ M : W = \(\frac{15\; \times\; 27\; \times\; 7}{21\; \times\; 35\; \times\; 9}\)
⇒ M : W = 3 : 7