PSLE Albert had orange pencils and gold pencils for sale. He sold 90 orange pencils. 70% of the pencils sold were gold.
- How many orange pencils and gold pencils did Albert sell altogether?
- He sold 50% of his pencils. 70% of the pencils left unsold were orange. How many gold pencils did Albert have at first?
|
Orange |
Gold |
Total |
Total in percent |
Before |
10 u |
10 u |
20 u |
100% |
Change |
- 30% - 3 u |
- 70% - 7 u |
- 100% - 10 u |
- 50% |
After |
70% 7 u |
30% 3 u |
100% 10 u |
50%
|
70% =
70100 =
710 Total number of pencils sold = 10 u
Number of gold pencils sold = 7 u
Number of orange pencils sold
= 10 u - 7 u
= 3 u
3 u = 90
1 u = 90 ÷ 3 = 30
Total number of pencils sold
= 10 u
= 10 x 30
= 300
(b)
Percent of the pencils left unsold = 100% - 50% = 50% 50% of the pencils that were sold = 10 u 50% of the pencils that were left unsold = 10 u Percent of the pencils left unsold that were orange = 70%
Percent of the pencils left unsold that were gold = 100% - 70% = 30%
Number of the pencils left unsold that were gold
= 30% x 10 u
=
30100 x 10 u
= 3 u
Number of gold pencils that Albert had at first
= 3 u + 7 u
= 10 u
= 10 x 30
= 300
Answer(s): (a) 300; (b) 300