Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 5 : 3.
The ratio of the number of girls to the number of boys in Class B is 3 : 7.
The number of girls is the same.
- Number of girls in Class A = _____ u
- Number of boys in Class B = _____ u
- Number of children in Class B = _____ u
- Total number of children = _____ u
Class A |
Class B |
Girls |
Boys |
Girls |
Boys |
5 x 3 |
3 x 3 |
3 x 5 |
7 x 5 |
15 u |
9 u |
15 u |
35 u |
(a)
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 5 and 3 = 15
Class A
Girls : Boys
5 : 3
(x3) 15 : 9
Class B
Girls : Boys
3 : 7
(x5) 15 : 35
Number of girls in Class A = 15 u
(b)
Number of boys in Class B = 35 u
(c)
Number of children in Class B
= 15 u + 35 u
= 50 u
(d)
Number of children in Class A
= 15 u + 9 u
= 24 u
Total number of children
= 50 u + 24 u
= 74 u
Answer(s): (a) 15; (b) 35; (c) 50; (d) 74