There are 70 people,
of which 20 are boys.
There are 30 more adults than girls.
- How many adults are there?
- How many children are there?
- How many more adults than children are there?
- How many less girls than boys are there?
(a)
Number of boys = 20
Number of girls = 1 u
Number of adults = 1 u + 30
Total number of people
= 20 + 1 u + 1 u + 30
= 1 u + 1 u + 20 + 30
= 2 u + 50
2 u + 50 = 70
2 u = 70 - 50
2 u = 20
1 u = 20 ÷ 2 = 10
Number of adults
= 1 u + 30
= 10 + 30
= 40
(b)
Number of children
= 20 + 10
= 30
(c)
Number of more adults than children
= 40 - 30
= 10
(d)
Number of less girls than boys
= 20 - 10
= 10
Answer(s): (a) 40; (b) 30; (c) 10; (d) 10