Probability Question


A 60 year old person has 1/20 risk to die during a certain year

The amount of sigarets smoked a day increases the risk with +1/20
Each cup of coffee lowers the risk with -0.2/20

If a certain 60 year old smokes 2 sigarets each day and drinks 3 cups of coffee what is his risk to die

==> Is this

1/20 + (2*1)/20 - (3*-0.2)/20 = 2,4/20 ?


Active Member
Hi Agave,

If I understand correctly the question, it doesn't make sense ...
I would prefer something like If you smoke each cigarette multiply the risk by 1.02 so if the basic risk is 1/20 the risk of one who smokes 3 cigarettes is 1.02^3 * 1/20

If you interpret the question the way you did, what is the risk of the dead to a man who drinks 10 cups of coffee? 1/20 -10*0.2/20 = -1/20?

Anyway even in the way yo did understand it, it should be only one minus. you did minus minus which is plus. (but the answer is ok)
Should be : 1/20 + (2*1)/20 - (3*0.2)/20 =2.4/20