Bryan's school organized a trip to Iran. 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, 49 boys decided to withdraw and 49 more girls decided to join in. In the end, the number of boys who participated became 30% of the total children for the trip. How many more girls than boys would visit Iran in the end?
|
Girls |
Boys |
Total |
Before |
7x5 = 35 u |
5x5 = 25 u |
12x5 = 60 u |
Change |
+ 7 u |
- 7 u |
|
After |
7x6 = 42 u |
3x6 = 18 u |
10x6 = 60 u |
30% =
30100 =
310Since 49 boys withdrew and another 49 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 10 is 60.
Number of boys who decided to withdraw
= 25 u - 18 u
= 7 u
7 u = 49
1 u = 49 ÷ 7 = 7
Number of more girls than boys in the end
= 42 u - 18 u
= 24 u
= 24 x 7
= 168
Answer(s): 168