Lucy had 80% as many sweets as Barbara. Lucy gave away 10% of her sweets and Barbara bought another 15 sweets. As a result, Lucy now has 60% as many sweets as Barbara. Find the number of sweets that Barbara had at first.
| |
Lucy |
Barbara |
| Before |
4x3 |
5x3 |
| Change |
- 0.4x3 |
+ 15 |
| After |
3.6x3 |
5x3 + 15 |
Comparing Lucy and
Barbara in the end |
3x3.6 |
5x3.6 |
| |
Lucy |
Barbara |
| Before |
12 u |
15 u |
| Change |
- 1.2 u |
+ 15 |
After
|
10.8 u
|
15 u + 15 =
18 u |
80% =
80100 =
4510% x 4
=
10100 x 4
= 0.4
60% =
60100 =
35The number of sweets that Lucy had in the end is repeated.
Make the number of sweets that Lucy had in the end the same.
The number of sweets that Barbara had in the end is repeated.
15 u + 15 = 18 u
18 u - 15 u = 15
3 u = 15
1 u = 15 ÷ 3 = 5
Number of sweets that Barbara had at first
= 15 u
= 15 x 5
= 75
Answer: 75
