Question

12) a and b working separately can finish a work in 8 and 12 days respectively. If they work for a day alternately (beginning with a), then in how many days will the work be completed

Answer 1

This is ur answer. Hope u got it

Answer 2

The work will be completed in 9.6 days.

Given:

Work done by A = 8 days

Work done by B = 12 days

To find:

If they work alternate, in how many days work will be completed.

Solution:

A can complete work in 8 days.

Percentage of work A completes in one day

= 100/8

= 12.5%

B can complete work in 12 days.

B's one day work

= 100/12

= 8.33%.

A and B together can complete

= 12. 5 + 8.33

= 20.83 % of work in one day.

Now,

Taking two days = 1 unit of time (one day of A and one of B).

In one unit of time, A and B can complete work = 20.83 %

Therefore,

Total time unit they need to complete the entire work

= 100/(20.83)

= 4.8

Thus,

Total time = 4.8 time unit

= 4.8 × 2

= 9.6

Answer: The work will be completed in 9.6 days.

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