Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 9 : 4.
The ratio of the number of girls to the number of boys in Class B is 7 : 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 |
9 x 7 |
4 x 7 |
7 x 9 |
10 x 9 |
63 u |
28 u |
63 u |
90 u |
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 9 and 7 = 63
Number of children in Class A
= 63 u + 28 u
= 91 u
Number of children in Class B
= 63 u + 90 u
= 153 u
Difference in the number of children in Class A and Class B
= 153 u - 91 u
= 62 u
(b)
Number of boys in Class A = 28 u
Number of boys in Class B = 90 u
Difference in the number of boys in Class A and Class B
= 90 u - 28 u
= 62 u
(c)
Number of girls in Class A = 63 uNumber of girls in Class B = 63 u Total number of girls = 63 u + 63 u= 126 u (d)
Total number of boys in Class A and Class B
= 90 u + 28 u
= 118 u
Answer(s)
: (a) 62; (b) 62; (c) 126; (d) 118