PSLE Rael kept his black and gold buttons in two boxes. The ratio of the number of black to gold buttons in the first box was 1 : 9 and it was 2 : 3 in the second box. The two boxes contained the same number of buttons. What fraction of Rael's buttons were black buttons?
First box |
Second box |
1x10 10 u |
1x10 10 u |
10x1 |
5x2 |
Black |
Gold |
Black |
Gold |
1x1 |
9x1 |
2x2 |
3x2 |
1 u |
9 u |
4 u |
6 u |
The total number of buttons in the first box and the second box is the same. Make the total number of buttons in each box the same. LCM of 10 and 5 is 10.
Total number of black buttons
= 1 u + 4 u
= 5 u
Total number of buttons
= 10 u + 10 u
= 20 u
Fraction of Rael's buttons that were black buttons
=
520 =
14 Answer(s):
14