Question

2. A can do a piece of work in 20 days
and B alone can do it in 30 days. They
work at it together for 4 days and
then A leaves. In how many days will
B alone finish the remaining work?​

Answer 1

Answer:

i think 30 days only

Step-by-step explanation:

Answer 2

Correct Question:

A can do a piece of work in 20 days and B in 30 days. They work together for 7 days and then both leave the work. Then C alone finishes the remaining work in 10 days. In how many days will C finish the full work?

Answer:

Work of A per day is 1/20

Work of A per day is 1/20Work of B per day is 1/30

Work of A per day is 1/20Work of B per day is 1/30Together in 7 days is

Work of A per day is 1/20Work of B per day is 1/30Together in 7 days is7/20 +7/30=(21+14)/60=35/60

Work of A per day is 1/20Work of B per day is 1/30Together in 7 days is7/20 +7/30=(21+14)/60=35/60Balance work is 25/60=5/12

Work of A per day is 1/20Work of B per day is 1/30Together in 7 days is7/20 +7/30=(21+14)/60=35/60Balance work is 25/60=5/12C can do 5/12 work in 10 days

Work of A per day is 1/20Work of B per day is 1/30Together in 7 days is7/20 +7/30=(21+14)/60=35/60Balance work is 25/60=5/12C can do 5/12 work in 10 daysFull work =(12/5)*10=24 days