Answer:
40
Step-by-step explanation:
The remaining fraction is ...
1 - 2/5 - 1/4 = 20/20 -8/20 -5/20 = 7/20
If 7/20 of the boy's marbles is 14 marbles, he had 40 to start with.
(7/20)·marbles = 14
marbles = (20/7)·14 = 40 . . . . . multiply the above equation by 20/7
