Fill in the blanks.
The ratio of the number of boys to the number of girls in Class A is 5 : 3.
The ratio of the number of boys to the number of girls in Class B is 3 : 4.
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 |
5 x 3 |
3 x 3 |
3 x 5 |
4 x 5 |
15 u |
9 u |
15 u |
20 u |
(a)
Change ratio into units.
The number of boys in Class A and Class B is the same.
LCM of 5 and 3 = 15
Class A
Boys : Girls
5 : 3
(x3) 15 : 9
Class B
Boys : Girls
3 : 4
(x5) 15 : 20
Number of boys in Class A = 15 u
(b)
Number of girls in Class B = 20 u
(c)
Number of children in Class B
= 15 u + 20 u
= 35 u
(d)
Number of children in Class A
= 15 u + 9 u
= 24 u
Total number of children
= 35 u + 24 u
= 59 u
Answer(s): (a) 15; (b) 20; (c) 35; (d) 59