PSLE Ethan kept his black and red cards in two boxes. The ratio of the number of black to red cards in the first box was 1 : 5 and it was 1 : 9 in the second box. The two boxes contained the same number of cards. What fraction of Ethan's cards were red cards?
First box |
Second box |
1x30 30 u |
1x30 30 u |
6x5 |
10x3 |
Black |
Red |
Black |
Red |
1x5 |
5x5 |
1x3 |
9x3 |
5 u |
25 u |
3 u |
27 u |
The total number of cards in the first box and the second box is the same. Make the total number of cards in each box the same.
LCM of 6 and 10 is 30.
Total number of red cards
= 25 u + 27 u
= 52 u
Total number of cards
= 30 u + 30 u
= 60 u
Fraction of Ethan's cards that were red cards
=
5260 =
1315 Answer(s):
1315