Xuan bought a total of 176 big and small chocolate bars. Then she decided to exchange 25% of her big chocolate bars for the small ones in the ratio of 1 : 4. After the exchange, she had 209 chocolate bars. What percentage of the chocolate bars she bought were small ones?
|
Big chocolate bars |
Small chocolate bars |
Total |
Before |
4 u |
? |
176 |
Change |
- 1 u |
|
|
Comparing big and small chocolate bars at exchange |
- 1 u |
+ 4 u |
+ 33 |
After |
3 u |
? |
209 |
25% =
25100 =
14The number of big chocolate bars that were exchanged for small chocolate bars was repeated.
Number of extra chocolate bars that Xuan received due to the exchange
= 4 u - 1 u
= 3 u
3 u = 209 - 176
3 u = 33
1 u = 33 ÷ 3 = 11
Number of small chocolate bars at first
= 176 - 4 u
= 176 - 4 x 11
= 176 - 44
= 132
Percentage of the chocolate bars Xuan bought that were small ones
=
132176 x 100%
= 75%
Answer(s): 75%