Options:
A) $ \frac{4}{5} $
B) $ \frac{3}{2} $
C) $ \frac{1}{5} $
D) $ \frac{2}{3} $
Show Answer
Answer:
Correct Answer: C
Solution:
- Number of four-digit numbers which are formed with
$ 1, $ $ 3, $ $ 5, $ $ 7, $ $ 9={}^{5}P _4 $
$ =5\times 4\times 3\times 2=120=n(s) $
The number which are divisible by $ 5={}^{4}P _3 $
$ =4\times 3\times 2=24=n(E) $
$ \therefore $ $ P(E)=\frac{n(E)}{n(S)}=\frac{24}{120}=\frac{1}{5} $