PSLE Henry kept his red and purple cards in two boxes. The ratio of the number of red to purple cards in the first box was 1 : 2 and it was 3 : 4 in the second box. The two boxes contained the same number of cards. What fraction of Henry's cards were red cards?
First box |
Second box |
1x21 21 u |
1x21 21 u |
3x7 |
7x3 |
Red |
Purple |
Red |
Purple |
1x7 |
2x7 |
3x3 |
4x3 |
7 u |
14 u |
9 u |
12 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 3 and 7 is 21.
Total number of red cards
= 7 u + 9 u
= 16 u
Total number of cards
= 21 u + 21 u
= 42 u
Fraction of Henry's cards that were red cards
=
1642 =
821 Answer(s):
821