Question

Two workers a and b manufactured a batch of identical parts a worked for 2 hours

Answer 1

15 hrs

if A can complete work alone in a days  

and  

B can complete work alone in b days, then  

2/a = 5/b = 1/2 or 1/a +5/2b = 1/4 ........... (1)

and  

3/a +3/b= 1/2 - 1/20 = 9/20 or 1/a +1/b = 9/60 .... ( 2)

From (1) and (2)

b=15 hrs and a= 12 hrs

is it right?

mark as brainliest