Question

Two men undertake to do a piece of work for Rs. 1,400. First man alone can do this work in 7 days while the second man alone can do this work in 8 days. If they working together complete this work in 3 days with the help of a boy, how should money be divided?

• A. Rs 600, Rs 550, Rs 250
• B. Rs 600, Rs 525, Rs 275
• C. Rs 600, Rs 500, Rs 300
• D. Rs 500, Rs 525, Rs 375

Answer 1

Answer: (B)

Rs 600, Rs 525, Rs 275

Answer 2

Money is divided in the ratio of amount of work done or in inverse ratio of number of days taken to do the work.
Let, the boy take b days to complete work.

\Rightarrow\;$$\frac{1}{7} + \frac{1}{8} + \frac{1}{b} = \frac{1}{3}

\Rightarrow\;$$\frac{1}{b} = \frac{11}{168}

\Rightarrow\;$$b = \frac{168}{11}

Ratio of days = $7:8:\frac{168}{11}$

Amount of Rs. 1400 is divided in inverse ratio:

$\frac{1}{7}:\frac{1}{8}:\frac{11}{168} = 24:21:11$

So the amount would be 600 , 525, 275 rupees.