Asked by Cass

Billy buys 3 doze light bulbs. After changing the lightbulbs in the house, he has 15 light bulbs left. How many lightbulbs did he use?

Multiply and Divide Interger problem. Please show me steps how to solve?
Answered by Ms. Sue
(3 * 12) - 15 = ?

36 - 15 = 21
Answered by Cass
Thank you. I think I forgot to show I multiplied 3 x 12 on my show work then. I put 36 (already multplied it)Hope I don't get a point off for that part.:(
Answered by Ms. Sue
You're welcome.