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 5 : 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 5 |
1 x 5 |
5 x 2 |
9 x 2 |
10 u |
5 u |
10 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 5 = 10
Class A
Boys : Girls
2 : 1
(x5) 10 : 5
Class B
Boys : Girls
5 : 9
(x2) 10 : 18
Number of boys in Class A = 10 u
(b)
Number of girls in Class B = 18 u
(c)
Number of children in Class B
= 10 u + 18 u
= 28 u
(d)
Number of children in Class A
= 10 u + 5 u
= 15 u
Total number of children
= 28 u + 15 u
= 43 u
Answer(s): (a) 10; (b) 18; (c) 28; (d) 43