Matthew's school organized a trip to Pakistan. At first, the ratio of the number of girls to the number of boys who planned to participate in the trip was 7 : 5. On the day of registration, 6 boys decided to withdraw and 6 more girls decided to join in. In the end, the number of boys who participated became 25% of the total children for the trip. How many more girls than boys would visit Pakistan in the end?
|
Girls |
Boys |
Total |
Before |
7x1 = 7 u |
5x1 = 5 u |
12x1 = 12 u |
Change |
+ 2 u |
- 2 u |
|
After |
3x3 = 9 u |
1x3 = 3 u |
4x3 = 12 u |
25% =
25100 =
14Since 6 boys withdrew and another 6 girls joined, the total number of children at first and in the end remains unchanged. Make the total number of children the same. LCM of 12 and 4 is 12.
Number of boys who decided to withdraw
= 5 u - 3 u
= 2 u
2 u = 6
1 u = 6 ÷ 2 = 3
Number of more girls than boys in the end
= 9 u - 3 u
= 6 u
= 6 x 3
= 18
Answer(s): 18