Xuan bought a total of 80 big and small jelly beans. Then she decided to exchange 75% of her big jelly beans for the small ones in the ratio of 3 : 8. After the exchange, she had 105 jelly beans. What percentage of the jelly beans she bought were small ones?
| |
Big jelly beans |
Small jelly beans |
Total |
| Before |
4 u |
? |
80 |
| Change |
- 3 u |
|
|
Comparing big and
small jelly beans at exchange |
- 3 u |
+ 8 u |
+ 25 |
| After |
1 u |
? |
105 |
75% =
75100 =
34The number of big jelly beans that were exchanged for small jelly beans was repeated.
Number of extra jelly beans that Xuan received due to the exchange
= 8 u - 3 u
= 5 u
5 u = 105 - 80
5 u = 25
1 u = 25 ÷ 5 = 5
Number of small jelly beans at first
= 80 - 4 u
= 80 - 4 x 5
= 80 - 20
= 60
Percentage of the jelly beans Xuan bought that were small ones
=
6080 x 100%
= 75%
Answer(s): 75%
