Question

The probability that a number selected at random from the set of members $\left\{1,2,3,....100\right\}$ is a cube is

• A. $\frac{1}{25}$
• B. $\frac{2}{25}$
• C. $\frac{3}{25}$
• D. $\frac{4}{25}$

Answer 1

The correct option is A $\frac{1}{25}$

Cube of $1=1$
Cube of $2=8$
Cube of $3=27$
Cube of $4=64$
Cube of $5=125$
So in set of members {1,2,3,... 100} only 4 numbers are cube of a natural number: $1,8,27,64$
Probability of selecting cubes in set of members {1,2,3,... 100} is $=\frac{4}{100}=\frac{1}{25}$