Yen baked 60 wafers. 25% of them were strawberry wafers. How many more strawberry wafers must Yen bake so that 85% of her wafers are strawberry wafers?
|
Strawberry wafers |
Other wafers |
Before |
25% |
75% |
Change |
+ ? |
No change |
After |
85 u |
15 u |
Number of strawberry wafers at first
= 25% x 60
=
25100 x 60
= 15
Percentage of other wafers
= 100% - 25%
= 75%
Number of other wafers
= 75% x 60
=
75100 x 60
= 45
Number of other wafers in the end
= 100 u - 85 u
= 15 u
The number of other wafers remains unchanged.
75% = 15 u
15 u = 45
1 u = 45 ÷ 15 = 3
Number of strawberry wafers in the end
= 85 u
= 85 x 3
= 255
Additional number of strawberry wafers that Yen must bake
= 255 - 15
= 240
Answer(s): 240