Question

Part 2: How many phone numbers can be made if the first digit must be 1, the second digit must

be a number in the range 3-5, the third digit must be a number in the range (6-9), and the last
seven digits can be any single digit number 0-9?
I

Answer 1

Explanation:

Answer 2

Answer: There are 21,000,000 phone numbers that can be made under the given constraints.

Explanation:

Given the first digit must be 1, the second digit must be a number in the range of 3-5, the third digit must be a number in the range of 6-9, and the last seven digits can be any single digit number 0-9.

There are 3 possible choices for the second digit (3, 4, or 5) and 4 possible choices for the third digit (6, 7, 8, or 9). For the last seven digits, there are 10 choices for each digit.

Therefore, the total number of phone numbers that can be made is:

1 x 3 x 4 x 10 x 10 x 10 x 10 x 10 x 10 x 10 = 21,000,000

Thus, there are 21,000,000 phone numbers that can be made under the given constraints.