Fiona bought a total of 20 big and small chocolate bars. Then she decided to exchange 75% of her big chocolate bars for the small ones in the ratio of 3 : 5. After the exchange, she had 24 chocolate bars. What percentage of the chocolate bars she bought were small ones?
|
Big chocolate bars |
Small chocolate bars |
Total |
Before |
4 u |
? |
20 |
Change |
- 3 u |
|
|
Comparing big and small chocolate bars at exchange |
- 3 u |
+ 5 u |
+ 4 |
After |
1 u |
? |
24 |
75% =
75100 =
34The number of big chocolate bars that were exchanged for small chocolate bars was repeated.
Number of extra chocolate bars that Fiona received due to the exchange
= 5 u - 3 u
= 2 u
2 u = 24 - 20
2 u = 4
1 u = 4 ÷ 2 = 2
Number of small chocolate bars at first
= 20 - 4 u
= 20 - 4 x 2
= 20 - 8
= 12
Percentage of the chocolate bars Fiona bought that were small ones
=
1220 x 100%
= 60%
Answer(s): 60%