Shiyun had 90% as many chocolate bars as Kylie. Shiyun gave away 20% of her chocolate bars and Kylie bought another 10 chocolate bars. As a result, Shiyun now has 70% as many chocolate bars as Kylie. Find the number of chocolate bars that Shiyun had in the end.
| |
Shiyun |
Kylie |
| Before |
9x7 |
10x7 |
| Change |
- 1.8x7 |
+ 10 |
| After |
7.2x7 |
10x7 + 10 |
Comparing Shiyun and
Kylie in the end |
7x7.2 |
10x7.2 |
| |
Shiyun |
Kylie |
| Before |
63 u |
70 u |
| Change |
- 12.6 u |
+ 10 |
After
|
50.4 u
|
70 u + 10 =
72 u |
90% =
90100 =
91020% x 9
=
20100 x 9
= 1.8
70% =
70100 =
710The number of chocolate bars that Shiyun had in the end is repeated.
Make the number of chocolate bars that Shiyun had in the end the same.
The number of chocolate bars that Kylie had in the end is repeated.
70 u + 10 = 72 u
72 u - 70 u = 10
2 u = 10
1 u = 10 ÷ 2 = 5
Number of chocolate bars that Shiyun had in the end
= 50.4 u
= 50.4 x 5
= 252
Answer: 252
