Q. In $x = 33^{n},n$ is a positive integral value, then what is the probability that $x$ will have 3 at its units place?

A) 1/3
B) $1/4$
C) 1/5
D) $1/2$
Explanation

(b)
Given that, $x = 33^{n}$
Where, $n$ is a positive integral value.
Here, only four digits may be at the unit place $ie,\ 1,\ 3,\ 7,\ 9.$
$\therefore n(S) = 4$
Let $E$ be the event of getting 3 at its units place.
$n(E) = 1$
$\therefore P(E) = \frac{n(E)}{n(S)} = \frac{1}{4}$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.