Answer:
15 min
Explanation:
Julia spends
in math.
and spends
in spelling.
Lets make
for calculation propuses.
Julia spends
doing her math and spelling homework.
And lets make

and

So, Julia spends
in reading.
If I divide an hour into 4 equal units, each unit equals 15 min, so 1 unit is 15 min.
Julia spends 15 min in reading.