Question

2. A can do a piece of work in 14 days while B can
do it in 21 days. They began together and worked
for 7 days. Then, A fell ill and B had to complete
the work. In how many days was the work
completed?​

Answer 1

Answer:

10.5

A work 14 days

and B work 21 day

Answer 2

Answer:

10.5 days

Given:

A can do a piece of work in 14 days and B can do a piece of work in 21 days And they worked together for 7 days

To find:

Work done by B

Solution:-

A one's day=1/14

B one's day=1/21

A and B total work=1/4+1/21

=5/42

They both work for 7 days

=5/42 ×7

=5/6

B had to complete the remaining work=1- 5/6

=1/6

B had to complete the work=1/6÷1/21

=1/6 × 21/1

=21/6

Total time taken by B=21/6+7

=(21+42)/6

=63/6

=10.5

________________

Time taken by B is 10.5 days