Robert had 5/6 as many erasers as Evan. When Evan gave half of his erasers to Robert, he then had 50 fewer erasers than his friend. How many erasers did Evan have at first?
Let Evan's erasers at first = E
Let Robert's at first = (5/6)E
When Evan gives (1/2) of his to Robert he has (1/2)E left and Robert has (5/6)E + (1/2)E
(1/2)E + 50 = (5/6)E + (1/2)E
50 (6/5) = E = 60 = what Evan had at first