jmc

Question

Adina and Lynn are going rock-climbing and need to rent special shoes. Lynn is normally size 9 and knows that her rock-climbing shoe-size is 42. If Adina is normally size 6, what size rock-climbing shoes should she rent assuming shoe size is directly proportional to rock-climbing shoe size?

Accepted Answer

Let x be Adina's rock-climbing size. The ratio of the girl's shoe sizes must be constant: Lynn's sizeAdina's size = 96=42x,so 9x=42 6, or x=42 69=28.