Fill in the blanks.
The ratio of the number of girls to the number of boys in Class A is 7 : 2.
The ratio of the number of girls to the number of boys in Class B is 8 : 9.
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 |
7 x 8 |
2 x 8 |
8 x 7 |
9 x 7 |
56 u |
16 u |
56 u |
63 u |
(a)
Change ratio into units.
The number of girls in Class A and Class B is the same.
LCM of 7 and 8 = 56
Class A
Girls : Boys
7 : 2
(x8) 56 : 16
Class B
Girls : Boys
8 : 9
(x7) 56 : 63
Number of girls in Class A = 56 u
(b)
Number of boys in Class B = 63 u
(c)
Number of children in Class B
= 56 u + 63 u
= 119 u
(d)
Number of children in Class A
= 56 u + 16 u
= 72 u
Total number of children
= 119 u + 72 u
= 191 u
Answer(s): (a) 56; (b) 63; (c) 119; (d) 191