Adam has 100 stickers in 3 colours.
30% of the stickers are blue.
The number of red stickers and green in the ratio of 3 : 7.
- What percentage of the stickers is green?
- How many red stickers are there?
Blue |
Red |
Green |
Total |
3 x 10 |
7 x 10 |
10 x 10 |
|
3 x 7 |
7 x 7 |
|
30 u |
21 u |
49 u |
100 u |
(a)
30% =
30100 =
310 The number of red and green stickers is the combined repeated identity.
Make the number of red and green stickers the same using the LCM of 7 and 10.
LCM of 7 and 10 = 70
Percentage of the stickers that is green
=
49100 x 100%
= 49%
(b)
Total number of stickers = 100 u
100 u = 100
1 u = 100 ÷ 100 = 1
Number of red stickers
= 21 u
= 21 x 1
= 21
Answer(s): (a) 49%; (b) 21