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-   -   Calculating the chance of survival? (https://www.usmle-forums.com/usmle-step-1-forum/26537-calculating-chance-survival.html)

 Evergreen 04-29-2012 06:08 PM

Calculating the chance of survival?

If the chance of surviving for 5 years after being diagnosed with colorectal cancer is 45% and the chance of surviving for 2 years after diagnosis is 75%, what is the chance of surviving for 5 years after diagnosis, given that the patients is alive at the end of the second year?

A) 15%
B) 30%
C) 45%
D) 60%
E) 75%

 Hope2Pass 04-29-2012 07:19 PM

B) 30% ... not too sure though ?

This is a good question .... I hate such questions.

 DocSikorski 04-29-2012 07:31 PM

wait, this wording is kinda weird,
is it just asking the same thing. "what is the chance of surviving for 5 years"? its what, still 45?

 Doc4Step1 04-29-2012 07:48 PM

27 % ... Not sure .:confused:

lol , thats not even an option.:P

 slowpoke 04-29-2012 08:12 PM

Should be 45 %

 Kabutar111 04-29-2012 08:45 PM

should be more than 45 % and less than 75 %

hmmmm :notsure::notsure: 60 %

no need to calculate this one came straight from kaplan

 steps_8186 04-30-2012 08:49 AM

yeah straight from kaplan.
the no. of ppl surviving at the end of 2 yrs=75(out of 100)
the no. of ppl surviving for another 3 yrs(i.e 5 yrs) are a subset of this no. =45/75=60%

 Kabutar111 04-30-2012 09:23 AM

Quote:
 Originally Posted by vna.rao22 (Post 114976) yeah straight from kaplan. the no. of ppl surviving at the end of 2 yrs=75(out of 100) the no. of ppl surviving for another 3 yrs(i.e 5 yrs) are a subset of this no. =45/75=60%
there is simple logic can be solved by
no need to calc
since already survived has to be more than 45 %
and since it can't be 75% as it is survival unto 2 years has to be less
so left with
ding dong 60%
this is how dr.D explain in video ;)

 Evergreen 04-30-2012 10:28 AM

Quote:
 Originally Posted by vna.rao22 (Post 114976) yeah straight from kaplan. the no. of ppl surviving at the end of 2 yrs=75(out of 100) the no. of ppl surviving for another 3 yrs(i.e 5 yrs) are a subset of this no. =45/75=60%
Good job!