There are four times as many children as adults in a safari park. There are 102 more boys than girls. If there are 490 people in the safari park,
- how many children are there?
- how many girls are there?
- how many boys are there?
Children |
Adults |
Total |
4 u |
1 u |
5 u |
Girls |
Boys |
|
|
1 p |
1 p + 102 |
|
|
(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 = 490
1 u = 490 ÷ 5 = 98
(a)
Number of children
= 4 u
= 4 x 98
= 392
(b)
Number of girls = 1 p
Number of boys = 1 p + 102
1 p + 1 p + 102 = 392
2 p + 102 = 392
2 p = 392 - 102
2 p = 290
1 p = 290 ÷ 2 = 145
Number of girls
= 1 p
= 145
(c)
Number of boys
= 1 p + 102
= 145 + 102
= 247
Answer(s): (a) 392; (b) 145; (c) 247