Question

A car hire firm has $2$ cars which it hires out day by day. If the number of demands for a car on each day follows poisson distribution with parameter $1.5$, then the probability that only one car is used is

• A. $e^{-1.5}$
• B. $1.5\times e^{-1.5}$
• C. $1-2.5\times e^{-1.5}$
• D. $1-1.5\times e^{-1.5}$

Answer 1

The correct option is B $1.5\times e^{-1.5}$

Here $\lambda =1.5$
Hence probability that only one car is used is $=P(X=1)=\frac{e^{-1.5}\left(1.5\right)}{1!}=1.5e^{-1.5}$