Xylia had 90% as many sweets as Irene. Xylia gave away 20% of her sweets and Irene bought another 30 sweets. As a result, Xylia now has 70% as many sweets as Irene. Find the number of sweets that Irene had at first.
| |
Xylia |
Irene |
| Before |
9x7 |
10x7 |
| Change |
- 1.8x7 |
+ 30 |
| After |
7.2x7 |
10x7 + 30 |
Comparing Xylia and
Irene in the end |
7x7.2 |
10x7.2 |
| |
Xylia |
Irene |
| Before |
63 u |
70 u |
| Change |
- 12.6 u |
+ 30 |
After
|
50.4 u
|
70 u + 30 =
72 u |
90% =
90100 =
91020% x 9
=
20100 x 9
= 1.8
70% =
70100 =
710The number of sweets that Xylia had in the end is repeated.
Make the number of sweets that Xylia had in the end the same.
The number of sweets that Irene had in the end is repeated.
70 u + 30 = 72 u
72 u - 70 u = 30
2 u = 30
1 u = 30 ÷ 2 = 15
Number of sweets that Irene had at first
= 70 u
= 70 x 15
= 1050
Answer: 1050
