Fill in the blanks.
Number of boys at first is 90% of the children.
Number of boys is then decreased to 65% of the children.
- Number of boys at first = _____ u
- Number of boys in the end = _____ u
- Decrease in the number of boys = _____ u
- Number of children in the end = _____ u
|
Boys |
Girls |
Before |
9 x 7 = 63 u |
1 x 7 = 7 u |
Change |
- ? |
No change |
After |
13 x 1 = 13 u |
7 x 1 = 7 u |
(a)
Change percentage into units.
90% =
90100 =
91065% =
65100 =
1320 Fraction of the children who are girls at first
= 1 -
910=
110 Fraction of the children who are girls in the end
= 1 -
1320=
720Number of girls at first and in the end remains the same.
The number of girls is the unchanged quantity.
LCM of 1 and 7 = 7
Number of boys at first = 63 u
(b)
Number of boys in the end = 13 u
(c)
Decrease in the number of boys
= 63 u - 13 u
= 50 u
(d)
Number of children in the end
= 13 u + 7 u
= 20 u
Answer(s): (a) 63; (b) 13; (c) 50; (d) 20