Question

14 A can do a work in 20 days and B can do the same
work in 30 days. In how many days can A and B
together do the work?
(a) 10
(b) 12 (c) 15 (d) 16
15 A and B can separately do a piece of work in 6 days
and 12 days, respectively. How long will they
together take to do the work?
(a) 9 days (b) 18 days (c) 6 days (d) 4 days
16 A can do a work in 20 days and B in 40 days. If
they work on it together for 5 days. Then, the
fraction of the work that left is​

Answer 1

Answer:

14) A's 1 days work =1/20

B's 1 days work =1/30

therefore,

(A+B)'s 1 days work = 1/20+ 1/30=3+2/60=1/12

So, the work will be completed in 12 days if they work together

hence option(B) is correct.