Fill in the blanks.
The ratio of the number of boys to the number of girls in Class A is 9 : 4.
The ratio of the number of boys to the number of girls in Class B is 5 : 8.
The number of boys is the same.
- Difference in the number of children in Class A and Class B = _____ u
- Difference in the number of girls in Class A and Class B = _____ u
- Total number of boys = _____ u
- Total number of girls = _____ u
(a)
Class A |
Class B |
Boys |
Girls |
Boys |
Girls |
9 x 5 |
4 x 5 |
5 x 9 |
8 x 9 |
45 u |
20 u |
45 u |
72 u |
Change ratio into units.
The number of boys in Class A and Class B is the same.
LCM of 9 and 5 = 45
Number of children in Class A
= 45 u + 20 u
= 65 u
Number of children in Class B
= 45 u + 72 u
= 117 u
Difference in the number of children in Class A and Class B
= 117 u - 65 u
= 52 u
(b)
Number of girls in Class A = 20 u
Number of girls in Class B = 72 u
Difference in the number of girls in Class A and Class B
= 72 u - 20 u
= 52 u
(c)
Number of boys in Class A = 45 uNumber of boys in Class B = 45 u Total number of boys = 45 u + 45 u= 90 u (d)
Total number of girls in Class A and Class B
= 72 u + 20 u
= 92 u
Answer(s)
: (a) 52; (b) 52; (c) 90; (d) 92