PSLE Gem has a number of pens in three colours: red, green and purple.
110 of the pens are red. The number of red pens is twice the number of green pens. What fraction of the pens is purple?
Red |
Green |
Purple |
Total |
1x2 |
9x2 |
10x2 |
2x1 |
1x1 |
|
|
2 u |
1 u |
17 u |
20 u |
Number of red pens is the repeated identity.
Make the number of red pens the same.
LCM of 1 and 2 = 2
Number of purple pens
= 20 u - 2 u - 1 u
= 17 u
Fraction of the pens that is purple
=
1720 Answer(s):
1720