Fill in the blanks.
Number of boys at first is 20% of the children.
Number of boys is then increased to 50%.
- Number of boys at first = _____ u
- Number of boys in the end = _____ u
- Increase in the number of boys = _____ u
- Number of children in the end = _____ u
|
Boys |
Girls |
Before |
1 x 1 = 1 u |
4 x 1 = 4 u |
Change |
+ ? |
No change |
After |
1 x 4 = 4 u |
1 x 4 = 4 u |
(a)
Change percentage into units.
20% =
20100 =
15 50% =
50100 =
12 Fraction of the children who are girls at first
= 1 -
15 =
45 Fraction of the children who are girls in the end
= 1 -
12=
12 Number of girls at first and in the end remains the same.
The number of girls is the unchanged quantity.
LCM of 4 and 1 = 4
Number of boys at first = 1 u
(b)
Number of boys in the end = 4 u
(c)
Increase in the number of boys
= 4 u - 1 u
= 3 u
(d)
Number of children in the end
= 4 u + 4 u
= 8 u
Answer(s): (a) 1; (b) 4; (c) 3; (d) 8