Q:

A) 18 days | B) 24 days |

C) 30 days | D) 36 days |

Answer: A) 18 days

Explanation:

Explanation:

2(A+B+C)'s 1 day work = 1/30 + 1/24 + 1/20 = 1/8

=>(A+B+C)'s 1 day's work= 1/16

work done by A,B and C in 10 days=10/16 = 5/8

Remaining work= 3/8

A's 1 day's work= $\left(\frac{1}{16}-\frac{1}{24}\right)=\frac{1}{48}$

Now, 1/48 work is done by A in 1 day.

So, 3/8 work wil be done by A in =48 x (3/8) = 18 days