Respuesta :
dozen = 12
12 x 3 = 36
36 light bulbs in total
15 left
so 36 - 15 = 21
answer = 21
12 x 3 = 36
36 light bulbs in total
15 left
so 36 - 15 = 21
answer = 21
Well, you know that 1 dozen = 12 items so if you have 3 dozen, that means 12 x 3 = 36 Set up an equation: 36 + x = 15 solve for x which represents the amount he used.