# Is this how you work out ratios? watch

1. Eg; number of seeds dark green = 28 yellow green = 56 yellow = 33.
To calculate the ratio dark green:yellow green:yellow you do:
28+58+33=119
119/28 = 4
119/58 = 2
119/33 = 4
Then simplify so the ratio is 22.
Is this how to work out ratios for all questions like this?
2. um, I don't think your calculation actually works! To find ratios I usually look for lowest common denominator

e.g. for 28 dark green seeds, 56 green, and 7 yellow, the LCD is 7 therefore ratio is:
41

edit: if you just look at the numbers you've got without doing calcs, you can see that the answer you've given CAN'T be right.
a ratio of 22 tells us there are half the number of yellow-green beans than either dark green or yellow, get you have 56 yellow-green beans and only 28 and 33 of the others respectively.
3. (Original post by starry skies)
um, I don't think your calculation actually works! To find ratios I usually look for lowest common denominator

e.g. for 28 dark green seeds, 56 green, and 7 yellow, the LCD is 7 therefore ratio is:
41

edit: if you just look at the numbers you've got without doing calcs, you can see that the answer you've given CAN'T be right.
a ratio of 22 tells us there are half the number of yellow-green beans than either dark green or yellow, get you have 56 yellow-green beans and only 28 and 33 of the others respectively.
But the mark scheme says the answer is 22???
4. I think you had better clarify with a teacher then, because I don't see how the figures you've given can tie in with that.
5. I mwan it says 11.
Damn, I did it wrong? But the lowest common denominator doesn't seem to work either. How else would you do it then?
6. what's the exact wording of the question? I would say that for a ratio of 11 to hold for your example, the figures would have to be 28 dark green, 56 yellow green and 28 yellow. If they're asking for a rough ESTIMATE of the ratio, then take your smallest number (here 28) and estimate how many times it "fits into" the other numbers, i.e. it fits into 56 two times, and into 33 roughly once

edit: facepalm, I've just realised your question is more about genetics than ratios really, in which case the rough estimate will give you the answer you're looking for.
7. using a simple example to clarify:

I have 3 apples, 2 pears and 1 banana. (obvious ratio= 31)

3+2+1=6
6/3=2
6/2=3
6/1=6

which gives 26 obviously not right, ok?

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Updated: June 10, 2008
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