The Crayola crayon company can make 2400 crayons in 4 minutes. How many crayons can they make in 15 minutes?

Set up a proportion and solve for n.

4 x n	=	2400 x 15	Find the cross products
4n	=	36000	Multiply
n	=	9000	Divide both sides by 4

The Crayola crayon company can make 9000 crayons in 15 minutes.

A typist can type 120 words in 100 seconds. At that rate, how many seconds would it take her to type 258 words?

Set up a proportion and solve for n.

120 x n	=	258 x 100	Find the cross products
120n	=	25800	Multiply
n	=	215	Divide both sides by 120

It would take her 215 seconds to type 258 words.