PSLE Xylia has a number of pens in three colours: blue, purple and red.
711 of the pens are blue. The number of blue pens is thrice the number of purple pens. What fraction of the pens is red?
Blue |
Purple |
Red |
Total |
7x3 |
4x3 |
11x3 |
3x7 |
1x7 |
|
|
21 u |
7 u |
5 u |
33 u |
Number of blue pens is the repeated identity.
Make the number of blue pens the same.
LCM of 7 and 3 = 21
Number of red pens
= 33 u - 21 u - 7 u
= 5 u
Fraction of the pens that is red
=
533 Answer(s):
533