Fill in the blanks.
The ratio of the number of boys to the number of girls in Class A is 8 : 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 |
8 x 5 |
1 x 5 |
5 x 8 |
9 x 8 |
40 u |
5 u |
40 u |
72 u |
(a)
Change ratio into units.
The number of boys in Class A and Class B is the same.
LCM of 8 and 5 = 40
Class A
Boys : Girls
8 : 1
(x5) 40 : 5
Class B
Boys : Girls
5 : 9
(x8) 40 : 72
Number of boys in Class A = 40 u
(b)
Number of girls in Class B = 72 u
(c)
Number of children in Class B
= 40 u + 72 u
= 112 u
(d)
Number of children in Class A
= 40 u + 5 u
= 45 u
Total number of children
= 112 u + 45 u
= 157 u
Answer(s): (a) 40; (b) 72; (c) 112; (d) 157