Is the answer 3/7 ???

Let there be total 100 rats.

Then, according to question
Male Rats = 40
Female Rats = 100- male rats = 100-40 = 60

Suppose, total number of dead rats = x
therefore, No. of dead male rats = (30/100)x= 0.3x
No. of dead female rats = x-0.3x = 0.7x

Death rate = (Dead rats)/(no. of rats to begin with)

Male death rate = (0.3x)/40
Female death rate = (0.7x)/60


Required ratio = (male death rate)/(female death rate)
= ((0.3x)/40)/((0.7x)/60)
= 9/14 .......................................... Ans.

FIRST OFF;

Please, when posting a question make sure to add:
1 question answer
2 source of questions
3 answer choices that are in the question (critical to understanding the whole idea of question)

for this question: picking smart numbers is key. (i M O)

pick 100 rats (classic smart number)
40 male
60 female

30 dead rat population and = 9 male and 21 female

so : 9 male : 21 female simplified to 3/7

This is the same thing as musicaemon but I looooove smart numbers!

Also: key to success on this question is understanding the question fully:
what was the ratio of the death rate among the male rats to the death rate among the female rats? Ponder it , synthesize it, fully understand then move into the question>

Enginpasa1 wrote:FIRST OFF;



30 dead rat population and = 9 male and 21 female

so : 9 male : 21 female simplified to 3/7

This is the same thing as musicaemon but I looooove smart numbers!

> [/b]

Engin,
Question asks ->
what was the ratio of the death rate among the male rats to the death rate among the female rats?

i.e what is the value of = male death rate/Female death rate ?

you will agree that,

Death rate = (Dead rats)/(no. of rats to begin with)

As per your number plugging data,
male death rate = 9/40
Female death rate = 21/60

Therefore,
male death rate/Female death rate = (9/40)/(21/60)= 9/14 .... Ans

having equations avoids the calculation mistake, that is very friendly aspect of equations.

nice catch. so i am wrong here but still would like to move forward picking numbers. can you show my way done the correct way?

one more time I am reminded of a bad habit of mine . I get a bit hasty in the excitement of the answer and miss key information. Clearly, there is no lack in math knowledge on my end, just a bit of carelessness or tendency to miss information.

Do you have any pointers musicdaemon? How do you not miss key informaiton?

guys,

how do you come up with:

male death = 9
Female death rate = 21

Its says 30% of the dead mice are male and 70% female. How do you know what x is, x being the number of dead mice? I get the solution via the equation but not he number picking ,spefically for the deadmice, i get the initall 100 = 40 + 60

thanks

Enginpasa1 wrote:
Do you have any pointers musicdaemon? How do you not miss key informaiton?

I guess my thought process converts all the words into equations. Here is I do it

1. work backwards , convert the final question in mathematical form, for this question:
what was the ratio of the death rate among the male rats to the death rate among the female rats?
so, what is ->(male death rate)/(female death rate)


2. Find out what each different term in step1 means with regard to question
so what is -> male death rate & female death rate
apply basics,
male death rate = (Dead male rats)/(no. of male rats to begin with)
and,
female death rate = (Dead female rats)/(no. of female rats to begin with)

here it is clear, that we have to put the data from the question, or in your case ENGIN plug in the numbers you want to play with.

3. Keep repeating step 2 until you get to the data plugging equation for this question step 2 suffices

4. Put the data provided, in the previous step, and move towards step2 -> step1 ...which is your final answer


This may look very long to you, but once in practice you only need to do it in your head,

i guess that helps you

freedsl wrote:guys,

how do you come up with:

male death = 9
Female death rate = 21

Its says 30% of the dead mice are male and 70% female. How do you know what x is, x being the number of dead mice? I get the solution via the equation but not he number picking ,spefically for the deadmice, i get the initall 100 = 40 + 60

thanks

you yourself have given the answer to your query, put any value for "x", Engin has put x = 30, you will get the answer even for x=10, 20,30,40....

i.e for integral -> (30% of x) = x*(30/100)

hope it is clear