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 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 |
7 x 5 |
5 x 5 |
5 x 7 |
9 x 7 |
35 u |
25 u |
35 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 5 = 35
Class A
Boys : Girls
7 : 5
(x5) 35 : 25
Class B
Boys : Girls
5 : 9
(x7) 35 : 63
Number of boys in Class A = 35 u
(b)
Number of girls in Class B = 63 u
(c)
Number of children in Class B
= 35 u + 63 u
= 98 u
(d)
Number of children in Class A
= 35 u + 25 u
= 60 u
Total number of children
= 98 u + 60 u
= 158 u
Answer(s): (a) 35; (b) 63; (c) 98; (d) 158