How many 7 digit phone numbers can be created if the first digit cannot be a zero, and the lastnumber must be an odd number?

Question

asked Feb 27, 2023 99.8k views

1 Answer

Slava Shpitalny · Answer 1 · 2023-03-04T04:37:03+0000

Given:

Number of digits = 7

The first digit cannot be zero

Last number = odd number

The possible numbers between other than zero is 9

and there are 5 odd numbers.

Hence, the number of possible combinations is:

$\begin{gathered} =\text{ 9 }*\text{ 10 }*\text{ 10 }*\text{ 10 }*\text{ 10 }*\text{ 10 }*\text{ 5} \\ =\text{ 4500000} \end{gathered}$

Answer: Option A