Gem bought a total of 80 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 : 7. After the exchange, she had 88 chocolate bars. What percentage of the chocolate bars she bought were small ones?
| |
Big chocolate bars |
Small chocolate bars |
Total |
| Before |
4 u |
? |
80 |
| Change |
- 3 u |
|
|
Comparing big and
small chocolate bars at exchange |
- 3 u |
+ 7 u |
+ 8 |
| After |
1 u |
? |
88 |
75% =
75100 =
34The number of big chocolate bars that were exchanged for small chocolate bars was repeated.
Number of extra chocolate bars that Gem received due to the exchange
= 7 u - 3 u
= 4 u
4 u = 88 - 80
4 u = 8
1 u = 8 ÷ 4 = 2
Number of small chocolate bars at first
= 80 - 4 u
= 80 - 4 x 2
= 80 - 8
= 72
Percentage of the chocolate bars Gem bought that were small ones
=
7280 x 100%
= 90%
Answer(s): 90%
