Xylia baked 120 cupcakes. 25% of them were butter cupcakes. How many more butter cupcakes must Xylia bake so that 70% of her cupcakes are butter cupcakes?
| |
Butter cupcakes |
Other cupcakes |
| Before |
25% |
75% |
| Change |
+ ? |
No change |
| After |
70 u |
30 u |
Number of butter cupcakes at first
= 25% x 120
=
25100 x 120
= 30
Percentage of other cupcakes
= 100% - 25%
= 75%
Number of other cupcakes
= 75% x 120
=
75100 x 120
= 90
Number of other cupcakes in the end
= 100 u - 70 u
= 30 u
The number of other cupcakes remains unchanged.
75% = 30 u
30 u = 90
1 u = 90 ÷ 30 = 3
Number of butter cupcakes in the end
= 70 u
= 70 x 3
= 210
Additional number of butter cupcakes that Xylia must bake
= 210 - 30
= 180
Answer(s): 180
