Question

A and B working separately can do a piece of work in 9 and 12 days
nspectively. If they work for a day alternatoly, A beginning, in how many days, the work
will be completed ? ​

Answer 1

Answer:

Percentage Method:

A can complete work in 9 days.

So, percentage of work A compltes in one day = 100/9 = 11.11%.

B can complete work in 12 days.

B's one day work = 100/12 = 8.33%.

A and B together can complete = 11.11 +8.33 = 19.44% of work in one day.

Now,

Take 2 days = 1 unit of time (one day of A and one of B).

In one unit of time A and B can complete work = 19.44% work.

Total time unit they need to complete whole work = 100/(19.44) = 5 time unit aprox.

Thus, Total time = 5 time unit = 5 *2 = 10 days.