Sunday

April 20, 2014

April 20, 2014

Posted by **Andrew** on Wednesday, November 14, 2012 at 11:12pm.

- math -
**Alexa**, Wednesday, November 14, 2012 at 11:17pmn!/r!(n-r)!

8!/4!(8-4)!

= 70

- math -
**Reiny**, Wednesday, November 14, 2012 at 11:18pmOk, Andrew

in my last answer to the same question I somehow missed the 7 and saw only 6 numbers.

(Have to concentrate more on reading the question more carefully)

In each case we can assume that no whole number starts with a zero, and no repeating digits for all 3 cases.

We have 8 digits, but can only use 7 in the first position ...

number of 4 digits numbers = 7x7x6x5 = 1470

number of 3 digit odd numbers, (must end in an odd) = 6x6x4 = 144

number of 3 digit numbers = 7x7x6 = 294

**Related Questions**

math - using digits 1-9 only once, multiply a 3 digit by a 2 digit number and ...

high school - Use the digits in the year 2010 and the operations +, -, x, ÷, ...

Algebra - Middle School - Use the digits in the year 2010 and the operations...

math - How many different 3 digit numbers less than 500 can be made using the ...

math - Any of the ten digits 0 through 9 may be used in a 6-digit code, but no ...

Math - What do the digits in the number 15 add up to? Answer 1+5=___. Using ...

math - a number rounds off to 4000.the digits in the hundreds place is twice the...

math - A number rounds off to 4000.The digits in the hundreds place is twice the...

Math - What is the least possible product for digits 1, 3, 5, 6, and 7 using all...

math. help please!! - Using only the digits 0 an 1, how many different numbers ...