There are 70 people,
of which 10 are boys.
There are 30 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 + 30
Total number of people
= 10 + 1 u + 1 u + 30
= 1 u + 1 u + 10 + 30
= 2 u + 40
2 u + 40 = 70
2 u = 70 - 40
2 u = 30
1 u = 30 ÷ 2 = 15
Number of adults
= 1 u
= 15
(b)
Number of children
= 10 + 1 u + 30
= 10 + 15 + 30
= 55
(c)
Number of less adults than children
= 55 - 15
= 40
(d)
Number of more girls than boys
= 1 u + 30 - 10
= 15 + 30 - 10
= 35
Answer(s): (a) 15; (b) 55; (c) 40; (d) 35