At the safari park, there were
511 as many girls as boys. After 78 girls came and 30 boys left the safari park, there was an equal number of girls and boys who remained at the safari park. How many children were at the safari park in the end?
| |
Girls |
Boys |
| Before |
5 u |
11 u |
| Change |
+ 78 |
- 30 |
| After |
5 u + 78 |
11 u - 30 |
Number of children in the end is the same.
11 u - 30 = 5 u + 78
11 u - 5 u = 78 + 30
6 u = 108
1 u = 108 ÷ 6 = 18
Number of children in the end
= 2 x (5 u + 78)
= 10 u + 156
= 10 x 18 + 156
= 180 + 156
= 336
Answer(s): 336
