Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 5 : 2.
The ratio of the number of girls to the number of boys in Class B is 7 : 8.
The number of girls is the same.
- Number of girls in Class A = _____ u
- Number of boys in Class B = _____ u
- Number of children in Class B = _____ u
- Total number of children = _____ u
Class A |
Class B |
Girls |
Boys |
Girls |
Boys |
5 x 7 |
2 x 7 |
7 x 5 |
8 x 5 |
35 u |
14 u |
35 u |
40 u |
(a)
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 5 and 7 = 35
Class A
Girls : Boys
5 : 2
(x7) 35 : 14
Class B
Girls : Boys
7 : 8
(x5) 35 : 40
Number of girls in Class A = 35 u
(b)
Number of boys in Class B = 40 u
(c)
Number of children in Class B
= 35 u + 40 u
= 75 u
(d)
Number of children in Class A
= 35 u + 14 u
= 49 u
Total number of children
= 75 u + 49 u
= 124 u
Answer(s): (a) 35; (b) 40; (c) 75; (d) 124