Answer:
0.1137= 11.37%
Step-by-step explanation:
Assuming there are 365 days in one year and every people have 1 birthday, then the chance for two people to have the same birthday is 1/365 and the chance they are not is 364/365. We are asked the chance for at least one match among 44 people. The opposite of the condition is that we have 0 matches and easier to calculate. The calculation will be:
P(X>=1)= ~P(X=0) = 1
P(X>=1)=- P(X=0)
P(X>=1)=1 - (364/365)^44
P(X>=1)=1- 0.8862
P(X>=1)=11.37%
To calculate the remaining caffeine, we use the radioactive decay formula which is expressed as An = Aoe^-kt where An is the amount left after t time, Ao is the initial amount and k is a constant we can calculate from the half-life information. We do as follows:
at half-life,
ln 1/2 = -k(6)
k = 0.12/hr
An = 80e^-0.12(14)
An = 15.87 mg
The correct answer is 16/81. Hope this helps.