Julian's school organized a trip to Finland. At first, the ratio of the number of boys to the number of girls who planned to participate in the trip was 7 : 5. On the day of registration, 28 girls decided to withdraw and 28 more boys decided to join in. In the end, the number of girls who participated became 35% of the total children for the trip. How many more boys than girls would visit Finland in the end?
|
Boys |
Girls |
Total |
Before |
7x5 = 35 u |
5x5 = 25 u |
12x5 = 60 u |
Change |
+ 4 u |
- 4 u |
|
After |
13x3 = 39 u |
7x3 = 21 u |
20x3 = 60 u |
35% =
35100 =
720Since 28 girls withdrew and another 28 boys 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 20 is 60.
Number of girls who decided to withdraw
= 25 u - 21 u
= 4 u
4 u = 28
1 u = 28 ÷ 4 = 7
Number of more boys than girls in the end
= 39 u - 21 u
= 18 u
= 18 x 7
= 126
Answer(s): 126