Joaquin buys 3 packs light bulbs. Each pack contains 12 light bulbs. After changing the bulbs in his house, he has 15 bulbs left. How many light bulbs did he use?

Respuesta :

Answer:

Step-by-step explanation:

3 times 12 equal 36.

36 minus 15 equals 21.

So Joaquin uses 21 light bulbs.