Fill in the blanks.
The ratio of the number of boys to the number of girls in Class A is 9 : 4.
The ratio of the number of boys to the number of girls in Class B is 6 : 7.
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 |
4 x 2 |
6 x 3 |
7 x 3 |
18 u |
8 u |
18 u |
21 u |
(a)
Change ratio into units.
The number of boys in Class A and Class B is the same.
LCM of 9 and 6 = 18
Class A
Boys : Girls
9 : 4
(x2) 18 : 8
Class B
Boys : Girls
6 : 7
(x3) 18 : 21
Number of boys in Class A = 18 u
(b)
Number of girls in Class B = 21 u
(c)
Number of children in Class B
= 18 u + 21 u
= 39 u
(d)
Number of children in Class A
= 18 u + 8 u
= 26 u
Total number of children
= 39 u + 26 u
= 65 u
Answer(s): (a) 18; (b) 21; (c) 39; (d) 65