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)