There are 990 people,
of which 100 are boys.
There are 420 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 = 100
Number of adults = 1 u
Number of girls = 1 u + 420
Total number of people
= 100 + 1 u + 1 u + 420
= 1 u + 1 u + 100 + 420
= 2 u + 520
2 u + 520 = 990
2 u = 990 - 520
2 u = 470
1 u = 470 ÷ 2 = 235
Number of adults
= 1 u
= 235
(b)
Number of children
= 100 + 1 u + 420
= 100 + 235 + 420
= 755
(c)
Number of less adults than children
= 755 - 235
= 520
(d)
Number of more girls than boys
= 1 u + 420 - 100
= 235 + 420 - 100
= 555
Answer(s): (a) 235; (b) 755; (c) 520; (d) 555