SOLUTION: How many numbers greater than 100 can be formed using the digits 1,2,3,4,5 if no digit may be repeated?

Question 958245: How many numbers greater than 100 can be formed using the digits 1,2,3,4,5 if no digit may be repeated?
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
1 digit numbers: can't do because we need the number to be bigger than 100

2 digit numbers: can't do because we need the number to be bigger than 100

3 digit number: so numbers like 123 or 345. We have 5 choices and 3 slots, so P(5,3) = (5!)/(5-3)! = (5!)/(2!) = 120/2 = 60. There are 60 different 3 digit numbers

4 digit numbers: P(5,4) = (5!)/(5-4)! = (5!)/(1!) = 120/1 = 120. There are 120 different 4 digit numbers

5 digit numbers: P(5,5) = (5!)/(5-5)! = (5!)/(0!) = 120/1 = 120. There are 120 different 5 digit numbers

-------------------------------------------------------------------------
Add up the results: 60+120+120 = 300

There are 300 different numbers that can be formed that are greater than 100. These numbers either have 3 digits, 4 digits or 5 digits.
RELATED QUESTIONS
How many 4-digit numbers greater than 6000 can be formed with the digits 1, 3, 6 and 8 if (answered by checkley77)

how many numbers greater 250 can be formed using the digits 1,2,3,4 if no digit is to be... (answered by greenestamps,Alan3354)

PLS HELP... ASAP... 1. Write all the three digit numbers using the digits 4,6 and 8... (answered by edjones)

How may three-digit numbers can be formed using the digits, 1, 2, 3, 4, and 5? Repeated... (answered by stanbon)

5. How many numbers may be formed by using 4 out of the 5 digits 1,2,3,4,5 (a) if the... (answered by Solver92311)

(i) Find how many different numbers can be formed using 4 of the digits 1, 2, 3, 4, 5, 6 (answered by ikleyn)

How many three-digit numbers can be formed using the digits 2,3,5,7,8 if the number is... (answered by ikleyn)

Find how many different odd 4-digit numbers less than 4000 can be made from the digits... (answered by Edwin McCravy)

How many 4-digit numbers greater than 6000 can be formed with the digits 1,3,6 and 8 if... (answered by checkley77)