There are 830 people,
of which 100 are girls.
There are 280 less adults than boys.
- How many adults are there?
- How many children are there?
- How many less adults than children are there?
- How many more boys than girls are there?
(a)
Number of girls = 100
Number of adults = 1 u
Number of boys = 1 u + 280
Total number of people
= 100 + 1 u + 1 u + 280
= 1 u + 1 u + 100 + 280
= 2 u + 380
2 u + 380 = 830
2 u = 830 - 380
2 u = 450
1 u = 450 ÷ 2 = 225
Number of adults
= 1 u
= 225
(b)
Number of children
= 100 + 1 u + 280
= 100 + 225 + 280
= 605
(c)
Number of less adults than children
= 605 - 225
= 380
(d)
Number of more boys than girls
= 1 u + 280 - 100
= 225 + 280 - 100
= 405
Answer(s): (a) 225; (b) 605; (c) 380; (d) 405