PSLE A bag contains erasers of three different colours.
15 of the erasers are yellow. The ratio of the number of red erasers to that of orange erasers is 2 : 5. What is the ratio of the number of yellow erasers to that of orange erasers?
Yellow |
Red |
Orange |
Total |
1x7 |
4x7 |
5x7 |
|
2x4 |
5x4 |
|
7 u |
8 u |
20 u |
35 u |
The total number of orange and red erasers is the combined repeated identity.
Make the total number orange and red erasers the same.
LCM of 4 and 7 = 28
Yellow : Orange
7 : 20
Answer(s): 7 : 20