Xylia bought a total of 225 big and small sweets. Then she decided to exchange 80% of her big sweets for the small ones in the ratio of 4 : 9. After the exchange, she had 270 sweets. What percentage of the sweets she bought were small ones?
| |
Big sweets |
Small sweets |
Total |
| Before |
5 u |
? |
225 |
| Change |
- 4 u |
|
|
Comparing big and
small sweets at exchange |
- 4 u |
+ 9 u |
+ 45 |
| After |
1 u |
? |
270 |
80% =
80100 =
45The number of big sweets that were exchanged for small sweets was repeated.
Number of extra sweets that Xylia received due to the exchange
= 9 u - 4 u
= 5 u
5 u = 270 - 225
5 u = 45
1 u = 45 ÷ 5 = 9
Number of small sweets at first
= 225 - 5 u
= 225 - 5 x 9
= 225 - 45
= 180
Percentage of the sweets Xylia bought that were small ones
=
180225 x 100%
= 80%
Answer(s): 80%
