Fill in the blanks.
The ratio of the number of boys to the number of girls in Class A is 2 : 1.
The ratio of the number of boys to the number of girls in Class B is 7 : 9.
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 |
2 x 7 |
1 x 7 |
7 x 2 |
9 x 2 |
14 u |
7 u |
14 u |
18 u |
(a)
Change ratio into units.
The number of boys in Class A and Class B is the same.
LCM of 2 and 7 = 14
Class A
Boys : Girls
2 : 1
(x7) 14 : 7
Class B
Boys : Girls
7 : 9
(x2) 14 : 18
Number of boys in Class A = 14 u
(b)
Number of girls in Class B = 18 u
(c)
Number of children in Class B
= 14 u + 18 u
= 32 u
(d)
Number of children in Class A
= 14 u + 7 u
= 21 u
Total number of children
= 32 u + 21 u
= 53 u
Answer(s): (a) 14; (b) 18; (c) 32; (d) 53