There are 70 people,
of which 20 are girls.
There are 40 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 = 20
Number of adults = 1 u
Number of boys = 1 u + 40
Total number of people
= 20 + 1 u + 1 u + 40
= 1 u + 1 u + 20 + 40
= 2 u + 60
2 u + 60 = 70
2 u = 70 - 60
2 u = 10
1 u = 10 ÷ 2 = 5
Number of adults
= 1 u
= 5
(b)
Number of children
= 20 + 1 u + 40
= 20 + 5 + 40
= 65
(c)
Number of less adults than children
= 65 - 5
= 60
(d)
Number of more boys than girls
= 1 u + 40 - 20
= 5 + 40 - 20
= 25
Answer(s): (a) 5; (b) 65; (c) 60; (d) 25