Question

A and B can do a piece of work in 30 days, while B and C can do the same work in 24 days and C and A in 20 days. They all work together for 10 days when B and C leave. How many days more will A take to finish the work?

18 days
24 days
30 days
36 days

Answer 1

Answer:

♠  The correct option is A.

Step-by-step explanation:

Let total work be 120 units  (LCM of 30, 24 and 20).

(A+B)'s one day work = 4 units

(B+C)'s one day work = 5 units

(C+A)'s one day work = 6 units

Adding all three equations and then dividing by 2,

(A+B+C)'s one day work = 7.5 units

A's one day work = 7.5 - 5 = 2.5 units

In 10 days, all three complete 75 units of work. Remaining 45 units can be completed by A in 18 days (at rate of 2.5 units per day).

Answer 2

$\huge\bf{Answer:-}$

Refer the attachment.