Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 7 : 5.
The ratio of the number of girls to the number of boys in Class B is 4 : 9.
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 4 |
5 x 4 |
4 x 7 |
9 x 7 |
28 u |
20 u |
28 u |
63 u |
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 7 and 4 = 28
Number of children in Class A
= 28 u + 20 u
= 48 u
Number of children in Class B
= 28 u + 63 u
= 91 u
Difference in the number of children in Class A and Class B
= 91 u - 48 u
= 43 u
(b)
Number of boys in Class A = 20 u
Number of boys in Class B = 63 u
Difference in the number of boys in Class A and Class B
= 63 u - 20 u
= 43 u
(c)
Number of girls in Class A = 28 uNumber of girls in Class B = 28 u Total number of girls = 28 u + 28 u= 56 u (d)
Total number of boys in Class A and Class B
= 63 u + 20 u
= 83 u
Answer(s)
: (a) 43; (b) 43; (c) 56; (d) 83