Fill in the blanks.
Number of girls at first is 90% of the children.
Number of girls is then decreased to 70% of the children.
- Number of girls at first = _____ u
- Number of girls in the end = _____ u
- Decrease in the number of girls = _____ u
- Number of children in the end = _____ u
|
Girls |
Boys |
Before |
9 x 3 = 27 u |
1 x 3 = 3 u |
Change |
- ? |
No change |
After |
7 x 1 = 7 u |
3 x 1 = 3 u |
(a)
Change percentage into units.
90% =
90100 =
91070% =
70100 =
710 Fraction of the children who are boys at first
= 1 -
910=
110 Fraction of the children who are boys in the end
= 1 -
710=
310Number of boys at first and in the end remains the same.
The number of boys is the unchanged quantity.
LCM of 1 and 3 = 3
Number of girls at first = 27 u
(b)
Number of girls in the end = 7 u
(c)
Decrease in the number of girls
= 27 u - 7 u
= 20 u
(d)
Number of children in the end
= 7 u + 3 u
= 10 u
Answer(s): (a) 27; (b) 7; (c) 20; (d) 10