Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 3 : 1.
The ratio of the number of girls to the number of boys in Class B is 4 : 5.
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 |
3 x 4 |
1 x 4 |
4 x 3 |
5 x 3 |
12 u |
4 u |
12 u |
15 u |
(a)
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 3 and 4 = 12
Class A
Girls : Boys
3 : 1
(x4) 12 : 4
Class B
Girls : Boys
4 : 5
(x3) 12 : 15
Number of girls in Class A = 12 u
(b)
Number of boys in Class B = 15 u
(c)
Number of children in Class B
= 12 u + 15 u
= 27 u
(d)
Number of children in Class A
= 12 u + 4 u
= 16 u
Total number of children
= 27 u + 16 u
= 43 u
Answer(s): (a) 12; (b) 15; (c) 27; (d) 43