Question

Out of the Numbers $1$ to $150$, one is to be selected at random. The probability that the number selected is perfectly divisible by $10$ is.......

• A. $\frac{2}{15}$
• B. $\frac{1}{15}$
• C. $\frac{1}{5}$
• D. $\frac{1}{10}$

Answer 1

The correct option is D $\frac{1}{10}$

Total numbers are $n\left(S\right)=150$

Numbers divisible by $10$ from $1$ to $150$ are$\{10,20,30,40,50,60,70,80,90,100,110,120,130,140,150\}$,

$n\left(E\right)=15$

Hence the probability that the number selected is perfectly divisible by 10 is $\frac{n\left(E\right)}{n\left(S\right)}=\frac{15}{150}=\frac{1}{10}$