Question

If you randomly pick a number from 1 to 25, what is the probability that the number will have “2” as one of the digits?

Answer 1

Answer:

$\frac{7}{25}$

Step-by-step explanation:

In the interval $n\in [1, 25]$, there are $(25-1)+1=25$ numbers total. The number $2$ appears as the ones digit for $3$ numbers in this interval: $0\bold{2}, 1\bold{2}, 2\bold{2}$. The subset $n\in [20, 25]$ marks the interval of numbers in the set that has the number $2$ as the tens digit. There are $(5-1)+1=5$ numbers in this set. Since $22$ is counted twice, there are a total of $5+3-1=7$ numbers in the original interval that contain the number $2$. Therefore, the probability a random selected number from the interval has the number $2$ in it is $\fbox{ \frac{7}{25} }$.

Answer 2

7/25 because that is the about of numbers that have a two in it