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?

Marss
Nov 27, 2018

#1**+7 **

**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?**

1) For the first digit, we have only one choice -- we must choose a 1.

2) For the second digit, we have three choicees -- we must choose 3, 4, or 5.

3) For the third digit, we have four choices -- we can choose 6, 7, 8, or 9.

4) For the fourth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

5) For the fifth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

6) For the sixth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

7) For the seventh digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

8) For the eighth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

9) For the ninth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

10) For the tenth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

1 X 3 X 4 X 10 X 10 X 10 X 10 X 10 X 10 X 10 = 120 000 000 possible numbers.

heureka
Nov 27, 2018

#1**+7 **

Best Answer

**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?**

1) For the first digit, we have only one choice -- we must choose a 1.

2) For the second digit, we have three choicees -- we must choose 3, 4, or 5.

3) For the third digit, we have four choices -- we can choose 6, 7, 8, or 9.

4) For the fourth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

5) For the fifth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

6) For the sixth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

7) For the seventh digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

8) For the eighth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

9) For the ninth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

10) For the tenth digit, we have ten choices -- we can choose 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9 .

1 X 3 X 4 X 10 X 10 X 10 X 10 X 10 X 10 X 10 = 120 000 000 possible numbers.

heureka
Nov 27, 2018