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?
Answer
She can buy 6 sweaters if she buys only one skirt.
When she buys 2 skirts, she can afford to buy 3 sweaters. And when she buys 3 skirts, she can’t afford to buy any sweaters. So, she can either buy 1 skirt or 3 sweaters for the same price.