PSLE Brandon kept his red and silver buttons in two boxes. The ratio of the number of red to silver buttons in the first box was 5 : 7 and it was 1 : 3 in the second box. The two boxes contained the same number of buttons. What fraction of Brandon's buttons were red buttons?
First box |
Second box |
1x12 12 u |
1x12 12 u |
12x1 |
4x3 |
Red |
Silver |
Red |
Silver |
5x1 |
7x1 |
1x3 |
3x3 |
5 u |
7 u |
3 u |
9 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 12 and 4 is 12.
Total number of red buttons
= 5 u + 3 u
= 8 u
Total number of buttons
= 12 u + 12 u
= 24 u
Fraction of Brandon's buttons that were red buttons
=
824 =
13 Answer(s):
13