A can do a certain job in 25 days which B alone can do in 20 days. A started the work and was joined
by B after 10 days. The number of days taken in completing the wotk were ?	Choose the correct choice from the following answers
A) 1423kmph	B) 1523kmph	C) 1623kmph	D) 1723kmph	E) None of these
Explanation:   Work done by A in l0 days = (1/25) *10 = 2/5   Remaining work = 1 - (2/5) = 3/5   (A+B)s 1 days work = (1/25) + (1/20) = 9/100   9/100 work is done by them in 1 day   hence 3/5 work will be done by them in (3/5)*(100/9)   = 20/3days.   Total time taken = (10 + 20/3) = 16*(2/3) days   Answer: 1623kmph
<result>C</result>
A can do a certain job in 25 days which B alone can do in 20 days. A started the work and was joined
by B after 10 days. The number of days taken in completing the wotk were ?