Lucy had 80% as many chocolate bars as Yen. Lucy gave away 10% of her chocolate bars and Yen bought another 15 chocolate bars. As a result, Lucy now has 60% as many chocolate bars as Yen. Find the number of chocolate bars that Yen had at first.
| |
Lucy |
Yen |
| Before |
4x3 |
5x3 |
| Change |
- 0.4x3 |
+ 15 |
| After |
3.6x3 |
5x3 + 15 |
Comparing Lucy and
Yen in the end |
3x3.6 |
5x3.6 |
| |
Lucy |
Yen |
| 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 chocolate bars that Lucy had in the end is repeated.
Make the number of chocolate bars that Lucy had in the end the same.
The number of chocolate bars that Yen 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 chocolate bars that Yen had at first
= 15 u
= 15 x 5
= 75
Answer: 75
