Morad and elias are car mechanics. morad can complete a certain task in x hours. elias can complete the same task in y hours. which equation correctly describes their combined hourly rate of work ? a) x+y=x+y b) 1/x + 1/y = 1/xy c) 1/x + 1/y = x+y/xy d) 1/x + 1/y = 1/x+y

C) 1/x + 1/y = x+y/x.y is the right answer. Why?

1- Morad will complete his task It's C)   1/x + 1/y = x+y/xy. Why?

Morad complted his task in in "x" hours.  and
 
in 1 hour he will complete 1/x of the task

2- Elias completed his task in in "y" hours.  and 
 
in 1 hour he will complete 1/y of the task:

3- 1/x + 1/y = (x+y)/xy ( reduce to same denominator)

Hmm i believe it would be c