Esther baked 150 shortbreads. 40% of them were blueberry shortbreads. How many more blueberry shortbreads must Esther bake so that 85% of her shortbreads are blueberry shortbreads?
| |
Blueberry shortbreads |
Other shortbreads |
| Before |
40% |
60% |
| Change |
+ ? |
No change |
| After |
85 u |
15 u |
Number of blueberry shortbreads at first
= 40% x 150
=
40100 x 150
= 60
Percentage of other shortbreads
= 100% - 40%
= 60%
Number of other shortbreads
= 60% x 150
=
60100 x 150
= 90
Number of other shortbreads in the end
= 100 u - 85 u
= 15 u
The number of other shortbreads remains unchanged.
60% = 15 u
15 u = 90
1 u = 90 ÷ 15 = 6
Number of blueberry shortbreads in the end
= 85 u
= 85 x 6
= 510
Additional number of blueberry shortbreads that Esther must bake
= 510 - 60
= 450
Answer(s): 450
