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 $15$ or $10$ is........

• A. $\frac{2}{15}$
• B. $\frac{1}{15}$
• C. $\frac{1}{5}$
• D. $\frac{1}{6}$

Answer 1

The correct option is A $\frac{2}{15}$

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

Numbers divisible by $15$ or $10$ from $1$ to $150$ are$\{10,15,20,30,40,45,50,60,70,75,80,90,100,105,110,120,130,135,140,150\}$

$n\left(E\right)=20$

Hence the probability that the number selected is perfectly divisible by $15$ or $10$ is $\frac{n\left(E\right)}{n\left(S\right)}=\frac{20}{150}=\frac{2}{15}$