arkZO is correct, but the question asks you to solve an inequality for the solution.
M = Money for spending
S = Sweatshirt price
SH = Shorts price
CS = Cash spent
We know that you did not spend all your money, so:
1.) CS < M, or CS < 60 and CS > 0
2.) S = 6 + 2xSH (sweatshirt is 6 more than twice the shorts price)
We also know the items purchased, 1 sweatshirt and 1 pair of shorts, so:
3.) CS= S + SH (Cash spent total)
We can now start substituting
CS = 6 + 2xSH + SH (combine (2) and (3) )
CS = 6 + 3xSH
4.) SH = ( CS - 6 ) / 3
We know that the cash spent (CS) is between $0 and $60
0 < CS < 60
We now have an inequality to solve
0 < 6 + 3xSH < 60
0 < 3x(2 + SH) < 60
divide by 3 on each side
0 < (2 + SH) < 20
-2 < SH < 18
However, we know that the sweatshirt is greater than 0, so
0 < SH < 18
The shorts are less than 18 and greater than 0