Answer:
80
Step-by-step explanation:
If we assume that Tammy ate 12 of the cupcakes she baked, we can write an equation relating the numbers of cupcakes.
__
setup
Let S represent the number of cupcakes Stacey baked. Then S-48 is the number Tammy baked. After Tammy ate 12 of her own cupcakes, the number she had was (S -48) -12 = (S -60). Stacey had 4 times this number:
S = 4(S -60)
solution
240 = 3S . . . . . . simplify, add 240-S
80 = S . . . . . . . divide by 3
Stacey had 80 cupcakes.
_____
Additional comment
Tammy had 80-48 = 32. After Tammy ate 12, she had 20. Then Stacey had 80/20 = 4 times as many.
If Tammy ate 12 of Stacey's cupcakes, then Stacey started with 60.
