Problem solving...?

Question

2 persons, working together, finish a work for 12 days. After they work together for 2 days, the first worker leaves and the work is finished by the second worker. If you know that the second worker every day does 2/3 of the work of the first one, find how many days will he need to finish the work?

Answer 1

The rates of working of the two are 3 : 2.
Now, in a day lets say 3 + 2 = 5 parts of the entire job gets completed when they work together. Thus the job has 12 * 5 = 60 parts. Now in two days, the two finish 2 * 5 =10 parts, leaving B to complete the rest 50 parts himself. He will thus require an extra 50/2 = 25 days.