There are 90 people,
of which 10 are boys.
There are 70 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 = 10
Number of girls = 1 u
Number of adults = 1 u + 70
Total number of people
= 10 + 1 u + 1 u + 70
= 1 u + 1 u + 10 + 70
= 2 u + 80
2 u + 80 = 90
2 u = 90 - 80
2 u = 10
1 u = 10 ÷ 2 = 5
Number of adults
= 1 u + 70
= 5 + 70
= 75
(b)
Number of children
= 10 + 5
= 15
(c)
Number of more adults than children
= 75 - 15
= 60
(d)
Number of less girls than boys
= 10 - 5
= 5
Answer(s): (a) 75; (b) 15; (c) 60; (d) 5