PSLE David kept his black and silver balls in two boxes. The ratio of the number of black to silver balls in the first box was 1 : 2 and it was 1 : 5 in the second box. The two boxes contained the same number of balls. What fraction of David's balls were black balls?
First box |
Second box |
1x6 6 u |
1x6 6 u |
3x2 |
6x1 |
Black |
Silver |
Black |
Silver |
1x2 |
2x2 |
1x1 |
5x1 |
2 u |
4 u |
1 u |
5 u |
The total number of balls in the first box and the second box is the same. Make the total number of balls in each box the same. LCM of 3 and 6 is 6.
Total number of black balls
= 2 u + 1 u
= 3 u
Total number of balls
= 6 u + 6 u
= 12 u
Fraction of David's balls that were black balls
=
312 =
14 Answer(s):
14