Andy Bernard Cassandra
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At the start, the ratio A:B:C was 3:7:5 3x 7x 5x
Andy gave 1/6 of his (0.5x) to Bernard 2.5x 7.5x 5x
Bernard gave 7/15 of his (3.5x) to Cassandra 2.5x 4x 8.5x
Cassandra gave 30 of hers to Andy 2.5x+30 4x 8.5x-30
The ratio of Andy to Bernard in the end was 5:4
ANSWERS:
Andy to start: 3x=36
Bernard to start: 7x=84
Cassandra to start: 5x=60
CHECK:
Andy at end: 2.5x+30=60
Bernard at end: 4x=48
Cassandra at end: 8.5x-30=72
A:B:C at end: 60:48:72=5:4:6