Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 7 : 3.
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.
- 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 |
7 x 3 |
3 x 3 |
3 x 7 |
10 x 7 |
21 u |
9 u |
21 u |
70 u |
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 7 and 3 = 21
Number of children in Class A
= 21 u + 9 u
= 30 u
Number of children in Class B
= 21 u + 70 u
= 91 u
Difference in the number of children in Class A and Class B
= 91 u - 30 u
= 61 u
(b)
Number of boys in Class A = 9 u
Number of boys in Class B = 70 u
Difference in the number of boys in Class A and Class B
= 70 u - 9 u
= 61 u
(c)
Number of girls in Class A = 21 uNumber of girls in Class B = 21 u Total number of girls = 21 u + 21 u= 42 u (d)
Total number of boys in Class A and Class B
= 70 u + 9 u
= 79 u
Answer(s)
: (a) 61; (b) 61; (c) 42; (d) 79