Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 10 : 9.
The ratio of the number of girls to the number of boys in Class B is 3 : 10.
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 |
10 x 3 |
9 x 3 |
3 x 10 |
10 x 10 |
30 u |
27 u |
30 u |
100 u |
(a)
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 10 and 3 = 30
Class A
Girls : Boys
10 : 9
(x3) 30 : 27
Class B
Girls : Boys
3 : 10
(x10) 30 : 100
Number of girls in Class A = 30 u
(b)
Number of boys in Class B = 100 u
(c)
Number of children in Class B
= 30 u + 100 u
= 130 u
(d)
Number of children in Class A
= 30 u + 27 u
= 57 u
Total number of children
= 130 u + 57 u
= 187 u
Answer(s): (a) 30; (b) 100; (c) 130; (d) 187