Fill in the blanks.
The ratio of the number of boys to the number of girls in Class A is 7 : 5.
The ratio of the number of boys to the number of girls in Class B is 2 : 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 |
7 x 2 |
5 x 2 |
2 x 7 |
9 x 7 |
14 u |
10 u |
14 u |
63 u |
(a)
Change ratio into units.
The number of boys in Class A and Class B is the same.
LCM of 7 and 2 = 14
Class A
Boys : Girls
7 : 5
(x2) 14 : 10
Class B
Boys : Girls
2 : 9
(x7) 14 : 63
Number of boys in Class A = 14 u
(b)
Number of girls in Class B = 63 u
(c)
Number of children in Class B
= 14 u + 63 u
= 77 u
(d)
Number of children in Class A
= 14 u + 10 u
= 24 u
Total number of children
= 77 u + 24 u
= 101 u
Answer(s): (a) 14; (b) 63; (c) 77; (d) 101