Adam has 380 stickers in 3 colours.
20% of the stickers are green.
The number of red stickers and blue in the ratio of 1 : 7.
- What percentage of the stickers is blue?
- How many red stickers are there?
Green |
Red |
Blue |
Total |
1 x 2 |
4 x 2 |
5 x 2 |
|
1 x 1 |
7 x 1 |
|
2 u |
1 u |
7 u |
10 u |
(a)
20% =
20100 =
15 The number of red and blue stickers is the combined repeated identity.
Make the number of red and blue stickers the same using the LCM of 4 and 8.
LCM of 4 and 8 = 8
Percentage of the stickers that is blue
=
710 x 100%
= 70%
(b)
Total number of stickers = 10 u
10 u = 380
1 u = 380 ÷ 10 = 38
Number of red stickers
= 1 u
= 1 x 38
= 38
Answer(s): (a) 70%; (b) 38