Posted by Pamala on .
The ratio of red jelly beans to yellow ones is 3:4. If I eat 3 red ones and 6 yellow ones, the ratio is 4:5. How many yellow ones to begin with?

Math 
Reiny,
number of reds  3x
number of yellows  4x
(3x3)/(4x6) = 4/5
16x  24 = 15x  15
x = 9
number of reds at the start = 3(9) = 27
number of yellows at the start = 4(9) = 36
check: origianl ratio = 27/36 = 3/4
after "eating" ratio = 24/30 = 4/5