Nora bought a total of 250 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 : 7. After the exchange, she had 270 jelly beans. What percentage of the jelly beans she bought were small ones?
|
Big jelly beans |
Small jelly beans |
Total |
Before |
4 u |
? |
250 |
Change |
- 3 u |
|
|
Comparing big and small jelly beans at exchange |
- 3 u |
+ 7 u |
+ 20 |
After |
1 u |
? |
270 |
75% =
75100 =
34The number of big jelly beans that were exchanged for small jelly beans was repeated.
Number of extra jelly beans that Nora received due to the exchange
= 7 u - 3 u
= 4 u
4 u = 270 - 250
4 u = 20
1 u = 20 ÷ 4 = 5
Number of small jelly beans at first
= 250 - 4 u
= 250 - 4 x 5
= 250 - 20
= 230
Percentage of the jelly beans Nora bought that were small ones
=
230250 x 100%
= 92%
Answer(s): 92%