Fill in the blanks.
The ratio of the number of boys to the number of girls in Class A is 5 : 2.
The ratio of the number of boys to the number of girls in Class B is 2 : 3.
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 |
5 x 2 |
2 x 2 |
2 x 5 |
3 x 5 |
10 u |
4 u |
10 u |
15 u |
(a)
Change ratio into units.
The number of boys in Class A and Class B is the same.
LCM of 5 and 2 = 10
Class A
Boys : Girls
5 : 2
(x2) 10 : 4
Class B
Boys : Girls
2 : 3
(x5) 10 : 15
Number of boys in Class A = 10 u
(b)
Number of girls in Class B = 15 u
(c)
Number of children in Class B
= 10 u + 15 u
= 25 u
(d)
Number of children in Class A
= 10 u + 4 u
= 14 u
Total number of children
= 25 u + 14 u
= 39 u
Answer(s): (a) 10; (b) 15; (c) 25; (d) 39