Answer:2
Step-by-step explanation:
Given
Physics problem requires 20 min
Math problem require 10 min
suppose x question of Physics and y questions of Math are done
so according to the question

Time require for x Physics problem 
Time require for y Math problem 
so,

On solving (1) and (2)
we get
and 
Maximum no of Physics question which can be solved is 2
To get angle Y, you have to do 90 - 27 to get the other angle in the triangle and you get 63. Then you do 180 - (63+51) which is 66.
Angle Y = 66
The store cost .057 cents more.
The store is more expensive.