Zara bought a total of 20 big and small sweets. Then she decided to exchange 25% of her big sweets for the small ones in the ratio of 1 : 6. After the exchange, she had 30 sweets. What percentage of the sweets she bought were small ones?
| |
Big sweets |
Small sweets |
Total |
| Before |
4 u |
? |
20 |
| Change |
- 1 u |
|
|
Comparing big and
small sweets at exchange |
- 1 u |
+ 6 u |
+ 10 |
| After |
3 u |
? |
30 |
25% =
25100 =
14The number of big sweets that were exchanged for small sweets was repeated.
Number of extra sweets that Zara received due to the exchange
= 6 u - 1 u
= 5 u
5 u = 30 - 20
5 u = 10
1 u = 10 ÷ 5 = 2
Number of small sweets at first
= 20 - 4 u
= 20 - 4 x 2
= 20 - 8
= 12
Percentage of the sweets Zara bought that were small ones
=
1220 x 100%
= 60%
Answer(s): 60%
