Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 7 : 2.
The ratio of the number of girls to the number of boys in Class B is 2 : 3.
The number of girls is the same.
- Number of girls in Class A = _____ u
- Number of boys in Class B = _____ u
- Number of children in Class B = _____ u
- Total number of children = _____ u
Class A |
Class B |
Girls |
Boys |
Girls |
Boys |
7 x 2 |
2 x 2 |
2 x 7 |
3 x 7 |
14 u |
4 u |
14 u |
21 u |
(a)
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 7 and 2 = 14
Class A
Girls : Boys
7 : 2
(x2) 14 : 4
Class B
Girls : Boys
2 : 3
(x7) 14 : 21
Number of girls in Class A = 14 u
(b)
Number of boys in Class B = 21 u
(c)
Number of children in Class B
= 14 u + 21 u
= 35 u
(d)
Number of children in Class A
= 14 u + 4 u
= 18 u
Total number of children
= 35 u + 18 u
= 53 u
Answer(s): (a) 14; (b) 21; (c) 35; (d) 53