Mason's school organized a trip to Greece. At first, the ratio of the number of girls to the number of boys who planned to participate in the trip was 8 : 7. On the day of registration, 40 boys decided to withdraw and 40 more girls decided to join in. In the end, the number of boys who participated became 20% of the total children for the trip. How many children would visit Greece in the end?
|
Girls |
Boys |
Total |
Before |
8x1 = 8 u |
7x1 = 7 u |
15x1 = 15 u |
Change |
+ 4 u |
- 4 u |
|
After |
4x3 = 12 u |
1x3 = 3 u |
5x3 = 15 u |
20% =
20100 =
15Since 40 boys withdrew and another 40 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 15 and 5 is 15.
Number of boys who decided to withdraw
= 7 u - 3 u
= 4 u
4 u = 40
1 u = 40 ÷ 4 = 10
Number of children that would visit Greece in the end
= 12 u + 3 u
= 15 u
= 15 x 10
= 150
Answer(s): 150