Final answer:
To solve this problem, we can set up a system of equations. Let x represent the number of T-shirts sold and y represent the number of pairs of shorts sold. Using the given information and equations, we can solve for x and y to find that they sold 31 T-shirts and 22 pairs of shorts.
Step-by-step explanation:
To solve this problem, we can set up a system of equations. Let x represent the number of T-shirts sold and y represent the number of pairs of shorts sold. We are given two pieces of information: the total number of T-shirts sold and pairs of shorts sold is 53, and the total amount of money earned is $570.
We can write the following equations:
x + y = 53 (equation 1)
12x + 9y = 570 (equation 2)
From equation 1, we can solve for y:
y = 53 - x
Substitute this into equation 2:
12x + 9(53 - x) = 570
Distribute and simplify:
12x + 477 - 9x = 570
Combine like terms:
3x + 477 = 570
Subtract 477 from both sides:
3x = 93
Divide both sides by 3:
x = 31
Now we can substitute this value back into equation 1 to find y:
31 + y = 53
Subtract 31 from both sides:
y = 22
Therefore, they sold 31 T-shirts and 22 pairs of shorts.