Answer with Explanation:
2(A + B + C)'s 1 day's work = ( 1/30 + 1/24 + 1/20 ) = 15/120 = 1/8 .
Therefore, (A + B + C)'s 1 day's work = 1/2*8 = 1/16 .
Work done by A, B, C in 10 days = 10/16 = 5/8 .
Remaining work = (1 - 5/8) = 3/8 .
A's 1 day's work =(1/16 - 1/24 )= 1/48 .
Now,1/48 work is done by A in 1 day.
So, 3/8 work will be done by A in ( 48 x 3 ) = 18 Days.
2(A + B + C)'s 1 day's work = ( 1/30 + 1/24 + 1/20 ) = 15/120 = 1/8 .
Therefore, (A + B + C)'s 1 day's work = 1/2*8 = 1/16 .
Work done by A, B, C in 10 days = 10/16 = 5/8 .
Remaining work = (1 - 5/8) = 3/8 .
A's 1 day's work =(1/16 - 1/24 )= 1/48 .
Now,1/48 work is done by A in 1 day.
So, 3/8 work will be done by A in ( 48 x 3 ) = 18 Days.