There are 60 people,
of which 10 are boys.
There are 20 less adults than girls.
- How many adults are there?
- How many children are there?
- How many less adults than children are there?
- How many more girls than boys are there?
(a)
Number of boys = 10
Number of adults = 1 u
Number of girls = 1 u + 20
Total number of people
= 10 + 1 u + 1 u + 20
= 1 u + 1 u + 10 + 20
= 2 u + 30
2 u + 30 = 60
2 u = 60 - 30
2 u = 30
1 u = 30 ÷ 2 = 15
Number of adults
= 1 u
= 15
(b)
Number of children
= 10 + 1 u + 20
= 10 + 15 + 20
= 45
(c)
Number of less adults than children
= 45 - 15
= 30
(d)
Number of more girls than boys
= 1 u + 20 - 10
= 15 + 20 - 10
= 25
Answer(s): (a) 15; (b) 45; (c) 30; (d) 25