Let the number of apple pies x
Let the number of blue pies y
Since they sold 38 pies on Saturday, then
Add x and y, then equate the sum by 38

Since they sold each apple pie for $11 and each blueberry pie for $13
Since they collected $460 on Saturday, then
Multiply x by 11 and y by 13, then add the products and equate the sum by 460

Now, we have a system of equations to solve it
Multiply equation (1) by -13 to equate the coefficients of y in values and opposite them in signs to eliminate them

Add equations (2) and (3)

Divide both sides by -2

Substitute the value of x in equation (1) to find y

Subtract 17 from both sides

The y sold 17 apple pies and 21 blueberry pies
The answer is the last choice