Problem Solving

Forty percent of the rats included in an experiment were male rats. If some of the rats died during the experiment and 30 percent of the rats that died were male rats, what was the ratio of the death rate among the male rats to the death rate among the female rats?

40 Male and 60 Female Rats.
If x died in the experiment.
30% died were male hence 70% were female.

therefore the ration is [spoiler]3:7[/spoiler]

well I don't know the real/original answer to this one. Reason I posted it.
I think the question asks the ratio of death RATE between male and female rats.

So if x is the dead no. of rats,
death rate of male rats is = 0.3x/40
And
death rate of female rats is = 0.7x/60

Hence the ratio of death rate male: female works out to be (0.3x/40)/(0.7x/60) = 9/14.

will be happy if somebody else gets the same answer.

30% died were male hence 70% were female.

we are asked about the rate so the rate has to be obtained by the percent of death female/male rats to the total female/male rats population. Once these rates are obtained they have to be compared to get the ratio... I would go with

StoneBlack

Let X be the rates died, 30*x/100 is total male rats that died. So rate of male rats death is 30x/100*40

then 70*x/100 is total female rats that died. So rat of femal rats death is 70*x/100*60

The ratio of both would earn 9:14

9/14 it is

You could draw up a nice little 2X2 matrix with male;female, dead;not dead. But its not necessary. Its simply a weighted average problem.

9:14