Opal bought a total of 450 big and small jelly beans. Then she decided to exchange 80% of her big jelly beans for the small ones in the ratio of 4 : 7. After the exchange, she had 477 jelly beans. What percentage of the jelly beans she bought were small ones?
| |
Big jelly beans |
Small jelly beans |
Total |
| Before |
5 u |
? |
450 |
| Change |
- 4 u |
|
|
Comparing big and
small jelly beans at exchange |
- 4 u |
+ 7 u |
+ 27 |
| After |
1 u |
? |
477 |
80% =
80100 =
45The number of big jelly beans that were exchanged for small jelly beans was repeated.
Number of extra jelly beans that Opal received due to the exchange
= 7 u - 4 u
= 3 u
3 u = 477 - 450
3 u = 27
1 u = 27 ÷ 3 = 9
Number of small jelly beans at first
= 450 - 5 u
= 450 - 5 x 9
= 450 - 45
= 405
Percentage of the jelly beans Opal bought that were small ones
=
405450 x 100%
= 90%
Answer(s): 90%
