Molecules of a toxic chemical eventually decompose into inert substances. Suppose the decomposition time is exponentially distributed with a mean of 1/lambda. The half-life of such a persistent poison is that time beyond which the probability is .50 that a particular molecule will remain toxic. Find the half-life for chemicals whose molecules have an average decomposition time of

a)4.15 years

b)22.18 years

c)188.53 years

d)3027.66 years

Step-by-step explanation:

Formula :

So,

We are given that The half-life of such a persistent poison is that time beyond which the probability is .50 that a particular molecule will remain toxic i.e. P(X>t)=0.5

So,

Taking natural log both sides

a)

t=-(6) ln(0.5)=4.15 years

b)

t=-(32) ln(0.5)=22.18 years

c)

t=-(272) ln(0.5)=188.53 years

d)

t=-(4368) ln(0.5)=3027.66 years

you cant answer this dummy

step-by-step explanation:

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.