Question

How many positiv integers are there less than 900 such that all digits are odd?

Answer 1

There are 125 positive integers less than 900 in which all the digits are odd.

Step-by-step explanation:

To find the number of positive integers less than 900 in which all the digits are odd, we need to consider the possible values for each position. The units digit can be 1, 3, 5, 7, or 9, which gives us 5 options. The tens digit can also be 1, 3, 5, 7, or 9, and the hundreds digit can be 1, 3, 5, 7, or 9 as well. So, each position has 5 options, and since we have 3 positions (units, tens, and hundreds), the total number of integers is 5 x 5 x 5 = 125. Therefore, there are 125 positive integers less than 900 in which all the digits are odd.