There are thrice as many adults as children in a concert hall, and there are twice as many girls as boys. If there are 1644 people in the concert hall,
- how many adults are there?
- how many children are there?
- how many girls are there?
| Adults |
Children |
| |
Boys |
Girls |
| |
1 u |
2 u |
| 9 u |
3 u |
(a)
Number of boys = 1 u
Number of girls = 2 x 1 u = 2 u
Number of children = 2 u + 1 u = 3 u
Number of adults = 3 x 3 u = 9 u
People in the concert hall
= 3 u + 9 u
= 12 u
12 u = 1644
1 u = 1644 ÷ 12 = 137
Number of adults
= 9 u
= 9 x 137
= 1233
(b)
Number of children
= 3 u
= 3 x 137
= 411
(c)
Number of girls
= 2 u
= 2 x 137
= 274
Answer(s): (a) 1233; (b) 411; (c) 274
