Statistical and probability problems. Need help understanding.

Question

A girl has exactly enough money to buy three sweaters and two skirts, or three skirts and no sweaters. All sweaters are the same price, and all skirts are the same price.

What is the maximum number of sweaters she can buy if she buys only one skirt?

Please show your work and help me understand.

Answer 1

x is the sweater y is the skirt

3x+2y = 3y

3x = y <-- skirt is 3 times the price of the sweater

y=1

3x = 1

x=1/3

no sweaters