Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 4 : 3.
The ratio of the number of girls to the number of boys in Class B is 7 : 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 |
4 x 7 |
3 x 7 |
7 x 4 |
9 x 4 |
28 u |
21 u |
28 u |
36 u |
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 4 and 7 = 28
Number of children in Class A
= 28 u + 21 u
= 49 u
Number of children in Class B
= 28 u + 36 u
= 64 u
Difference in the number of children in Class A and Class B
= 64 u - 49 u
= 15 u
(b)
Number of boys in Class A = 21 u
Number of boys in Class B = 36 u
Difference in the number of boys in Class A and Class B
= 36 u - 21 u
= 15 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
= 36 u + 21 u
= 57 u
Answer(s)
: (a) 15; (b) 15; (c) 56; (d) 57