PSLE Luis kept his pink and black stars in two boxes. The ratio of the number of pink to black stars in the first box was 3 : 4 and it was 1 : 2 in the second box. The two boxes contained the same number of stars. What fraction of Luis's stars were black stars?
First box |
Second box |
1x21 21 u |
1x21 21 u |
7x3 |
3x7 |
Pink |
Black |
Pink |
Black |
3x3 |
4x3 |
1x7 |
2x7 |
9 u |
12 u |
7 u |
14 u |
The total number of stars in the first box and the second box is the same. Make the total number of stars in each box the same.
LCM of 7 and 3 is 21.
Total number of black stars
= 12 u + 14 u
= 26 u
Total number of stars
= 21 u + 21 u
= 42 u
Fraction of Luis's stars that were black stars
=
2642 =
1321 Answer(s):
1321