Ryan's school organized a trip to China. At first, the ratio of the number of boys to the number of girls who planned to participate in the trip was 8 : 7. On the day of registration, 76 girls decided to withdraw and 76 more boys decided to join in. In the end, the number of girls who participated became 15% of the total children for the trip. How many children would visit China in the end?
|
Boys |
Girls |
Total |
Before |
8x4 = 32 u |
7x4 = 28 u |
15x4 = 60 u |
Change |
+ 19 u |
- 19 u |
|
After |
17x3 = 51 u |
3x3 = 9 u |
20x3 = 60 u |
15% =
15100 =
320Since 76 girls withdrew and another 76 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 15 and 20 is 60.
Number of girls who decided to withdraw
= 28 u - 9 u
= 19 u
19 u = 76
1 u = 76 ÷ 19 = 4
Number of children that would visit China in the end
= 51 u + 9 u
= 60 u
= 60 x 4
= 240
Answer(s): 240