A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 5 years ago
Internal telephone numbers in a university are composed of 5 digits. The first two digits can form any integer between (and including) 61 and 75, the third digit is an integer between 1 and 9 and the last two each take any integer value. Assume that it is disallowed to have a phone number with last three digits being 100, 101, or 102. In such case, the total number of possible internal telephone numbers that start with the digit 7 is.....
anonymous
 5 years ago
Internal telephone numbers in a university are composed of 5 digits. The first two digits can form any integer between (and including) 61 and 75, the third digit is an integer between 1 and 9 and the last two each take any integer value. Assume that it is disallowed to have a phone number with last three digits being 100, 101, or 102. In such case, the total number of possible internal telephone numbers that start with the digit 7 is.....

This Question is Closed

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0is it 4500  15 = 4485

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.075 61  14+1 = 15 ways 1 to 9 = 9 ways (if we can count 1 and 9) 1000 ways  3 = 997 ways for the ending 15*9*997 is what it looks like to me

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0is 134,595 an option?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0the first digit starts with a 7 mate, so its 5 possible choices times by 9 possible choices times by 100 possible choices for the last 2 digits including "00", since i have to avoid 100,101,102, i got to take of 15 possibilities so its 450015 = 4485

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0yeah, start with a 7 ... to many numbers to sort thru lol 70 71 72 73 74 75 = 6 ways then 6.9.997 is what I would see then

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0the last 3 digits can be from 000 to 999 (1000), excluding the 3 ways mentioned = 997 ways

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.061 to 75 = 15 ways, exclude the 6s and we get 6 ways to start

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so its 5400  18 = 5382, its not multiple choice =\

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0wait, im still reading the question a little off. try this:

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0composed of 5 digits. first two digits, starts with a 7: 7 __ 6 ways 3rd digit between 1 and 9: 9 ways last two digits each take any integer value. Assume that it is disallowed to have a phone number with last three digits being 100, 101, or 102

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0100 to 999 is where I was off at,

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0000 to 099 is 100 excluded ways, + the 3 mentioned total 103 excluded ways 1000 103  897 ways total then sound right?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0im still including that 3rd digit ....

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.000 to 99 is the last 2 digit options (100); exclude 00,01,02 (3) 1003 = 97 ways 6.9.97 = 5238

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0thanks 5382 right? was that a typo error?
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.