Fill in the blanks.
The ratio of the number of boys to the number of girls in Class A is 9 : 2.
The ratio of the number of boys to the number of girls in Class B is 8 : 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 |
9 x 8 |
2 x 8 |
8 x 9 |
9 x 9 |
72 u |
16 u |
72 u |
81 u |
(a)
Change ratio into units.
The number of boys in Class A and Class B is the same.
LCM of 9 and 8 = 72
Class A
Boys : Girls
9 : 2
(x8) 72 : 16
Class B
Boys : Girls
8 : 9
(x9) 72 : 81
Number of boys in Class A = 72 u
(b)
Number of girls in Class B = 81 u
(c)
Number of children in Class B
= 72 u + 81 u
= 153 u
(d)
Number of children in Class A
= 72 u + 16 u
= 88 u
Total number of children
= 153 u + 88 u
= 241 u
Answer(s): (a) 72; (b) 81; (c) 153; (d) 241