Two workers A and B are engaged to do a work. A working alone takes 8 hours more to complete the job than if both worked together. If B worked alone he would need 5 hours more to complete the job than they both working together. What time would they take to do the work together?
সমাধান
সঠিক উত্তর: Option C
Let,
It takes x hours to complete the job when A and Bboth worked together.
A working alone takes x+8
B working alone takes x+4.5
A's works in 1 hour=1/(x+8)
Bs works in 1 hour=1/(x+4.5)
(A+B)'s works in 1 hour=1/x
we get,
1/(x+8)+1/(x+4.5)=1/x
so, x=6