Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 2 : 1.
The ratio of the number of girls to the number of boys in Class B is 9 : 10.
The number of girls is the same.
- Difference in the number of children in Class A and Class B = _____ u
- Difference in the number of boys in Class A and Class B = _____ u
- Total number of girls = _____ u
- Total number of boys = _____ u
(a)
Class A |
Class B |
Girls |
Boys |
Girls |
Boys |
2 x 9 |
1 x 9 |
9 x 2 |
10 x 2 |
18 u |
9 u |
18 u |
20 u |
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 2 and 9 = 18
Number of children in Class A
= 18 u + 9 u
= 27 u
Number of children in Class B
= 18 u + 20 u
= 38 u
Difference in the number of children in Class A and Class B
= 38 u - 27 u
= 11 u
(b)
Number of boys in Class A = 9 u
Number of boys in Class B = 20 u
Difference in the number of boys in Class A and Class B
= 20 u - 9 u
= 11 u
(c)
Number of girls in Class A = 18 uNumber of girls in Class B = 18 u Total number of girls = 18 u + 18 u= 36 u (d)
Total number of boys in Class A and Class B
= 20 u + 9 u
= 29 u
Answer(s)
: (a) 11; (b) 11; (c) 36; (d) 29