Fill in the blanks.
The ratio of the number of boys to the number of girls in Class A is 9 : 2.
The ratio of the number of boys to the number of girls in Class B is 2 : 5.
The number of boys is the same.
- Number of boys in Class A = _____ u
- Number of girls in Class B = _____ u
- Number of children in Class B = _____ u
- Total number of children = _____ u
Class A |
Class B |
Boys |
Girls |
Boys |
Girls |
9 x 2 |
2 x 2 |
2 x 9 |
5 x 9 |
18 u |
4 u |
18 u |
45 u |
(a)
Change ratio into units.
The number of boys in Class A and Class B is the same.
LCM of 9 and 2 = 18
Class A
Boys : Girls
9 : 2
(x2) 18 : 4
Class B
Boys : Girls
2 : 5
(x9) 18 : 45
Number of boys in Class A = 18 u
(b)
Number of girls in Class B = 45 u
(c)
Number of children in Class B
= 18 u + 45 u
= 63 u
(d)
Number of children in Class A
= 18 u + 4 u
= 22 u
Total number of children
= 63 u + 22 u
= 85 u
Answer(s): (a) 18; (b) 45; (c) 63; (d) 85