Collection 1, no of marbles = 125
Collection 2, no of marbles =36 fewer = 125-36 =89
Collection 3, no of marbles = 53 more =125+53 =178
Hence total marbles = 125+89+178
= 392
Given that he uses 14 trays to hold all the marables
Let us assume that he distributes equally all 392 marbles in 14 trays
Then marbles in each tray = 392/14 = 27
Thus division is used for finding out the no of marbles in a tray.
For finding out no of marbles in 3 trays, we get = 3x27 = 81 marbles
(Here direct variation is used)
Answer is 81 marbles