Answer:
Julian has 16 dimes and 6 quarters
Explanation:
Let's suppose Julian has q quarters and d dimes
The total coins are 22, that is
q+d=22
q=22-d [1]
The total amount of money he has is 310 cents which are made of 10d dimes and 25q quarters
10d+25q=310
Simplifying by 5
2d+5q=62
Using the relation [1]
2d+5(22-d)=62
2d+110-5d=62
3d=48 => d=16
q=22-16 = 6
So Julian has 16 dimes and 6 quarters