There are four times as many children as adults in a safari park. There are 172 more girls than boys. If there are 570 people in the safari park,
- how many children are there?
- how many boys are there?
- how many girls are there?
Children |
Adults |
Total |
4 u |
1 u |
5 u |
Boys |
Girls |
|
|
1 p |
1 p + 172 |
|
|
(a)
Number of adults = 1 u
Number of children = 4 x 1 u = 4 u
Total number of people
= 4 u + 1 u
= 5 u
5 u = 570
1 u = 570 ÷ 5 = 114
(a)
Number of children
= 4 u
= 4 x 114
= 456
(b)
Number of boys = 1 p
Number of girls = 1 p + 172
1 p + 1 p + 172 = 456
2 p + 172 = 456
2 p = 456 - 172
2 p = 284
1 p = 284 ÷ 2 = 142
Number of boys
= 1 p
= 142
(c)
Number of girls
= 1 p + 172
= 142 + 172
= 314
Answer(s): (a) 456; (b) 142; (c) 314