Question

How many possible phone numbers are there in a city that has two area codes?
A.) 180,000
B.) 9,565,938
C.) 18,000,000
D.) 20,000,000

Answer 1

The only differences in the phone numbers are the last 3 digits. How many possible phone numbers can be assigned using this system?

10 * 10 * 10 = 1000

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Many large cities have run out of phone numbers and so a new area code must be introduced. How many different phone numbers are there in a single area code if the first digit cannot be zero?

(area code) _ _ _ - _ _ _ _

First digit cannot be zero (must be 1-9)
All other digits can be 0-9

9 * 10 * 10 * 10 * 10 * 10 * 10 = 9,000,000

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How many different phone numbers are possible using a 3-digit area code and a 7-digit phone number if the first digit of the area code and phone number cannot be zero?

_ _ _ - _ _ _ - _ _ _ _

^ ........ ^ : Digits 1 through 9
All others: Digits 0 through 9

9 * 10 * 10 * 9 * 10 * 10 * 10 * 10 * 10 * 10 = 8,100,000,000

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A shipping service offers to send packages by ground delivery using 2 different companies, by next day air using 3 different companies, and by 2-day air using 3 different companies. How many different shipping options does the company offer?

Since all methods of delivery are independent, just add them (i.e. you will NOT be using ground delivery AND 2-day air delivery, or next day air delivery AND 2-day air delivery).

2 + 3 + 3 = 8

Answer 2

Medal?

Answer 3

Each area code has about 7,800,000

Answer 4

Seriously? http://answers.yahoo.com/question/index?qid=20110506135531AAHVMGG

Answer 5

That's my works cited page.

Answer 6

I was going to post it; so others wouldn't be calling it (plagiarism)!

Answer 7

You're implying that you wrote that on yahoo?