Barbara baked 40 muffins. 25% of them were blueberry muffins. How many more blueberry muffins must Barbara bake so that 70% of her muffins are blueberry muffins?
| |
Blueberry muffins |
Other muffins |
| Before |
25% |
75% |
| Change |
+ ? |
No change |
| After |
70 u |
30 u |
Number of blueberry muffins at first
= 25% x 40
=
25100 x 40
= 10
Percentage of other muffins
= 100% - 25%
= 75%
Number of other muffins
= 75% x 40
=
75100 x 40
= 30
Number of other muffins in the end
= 100 u - 70 u
= 30 u
The number of other muffins remains unchanged.
75% = 30 u
30 u = 30
1 u = 30 ÷ 30 = 1
Number of blueberry muffins in the end
= 70 u
= 70 x 1
= 70
Additional number of blueberry muffins that Barbara must bake
= 70 - 10
= 60
Answer(s): 60
