Question

22. A can do of the work in 5 days and B can do
of the work in 10 days. In how many days
both A and B together can do the work?
(a) 77 days (b) 7 days
(c) 7 days (6) 7 days
(e) None of these​

Answer 1

Answer must be the average of 5 and 10

average = 5+10/2

= 15/2

= 7.5

It is not given in the options so the correct option must be (e) none of the above