Question

options are
1.5days ,2. 6days 3.8days, 4.9days ,5.None of these

Answer 1

firstly we will find 1 day work of both A and B, then by adding we can get collective days for them,

so,

A's 1 day work = 1/10

B's 1 day work = 1/15

(a+b)'s work =

1/10+1/15

find the LCM of 10 and 15

so the LCM is 30

3+2/30

=1/6

Please brain list if you are satisfied!