SOLUTION: How many 3-digit number can be formed from the digits 2,3,5,6,8 and 9 a) if repetition is not allowed? b) if repetition is allowed? c) how many digits in (a) are odd? d)how ma

Algebra ->  Probability-and-statistics -> SOLUTION: How many 3-digit number can be formed from the digits 2,3,5,6,8 and 9 a) if repetition is not allowed? b) if repetition is allowed? c) how many digits in (a) are odd? d)how ma      Log On


   

Question 653761: How many 3-digit number can be formed from the digits 2,3,5,6,8 and 9
a) if repetition is not allowed?
b) if repetition is allowed?
c) how many digits in (a) are odd?
d)how many digits in (b) are greater than 500?
Answer by Edwin McCravy(20065) About Me  (Show Source):
You can put this solution on YOUR website!
How many 3-digit number can be formed from the digits 2,3,5,6,8 and 9
a) if repetition is not allowed?
Choose the 1st digit as any of the 6 digits.
Choose the 2nd digit any of the remaining 5 digits.
Choose the 3rd digit any of the remaining 4 digits.:

6󬊄 = 120

b) if repetition is allowed?
Choose the 1st digit as any of the 6 digits.
Choose the 2nd digit as any of the 6 digits.
Choose the 3rd digit as any of the 6 digits.:

6󬝲 = 216

c) how many digits in (a) are odd?
Choose the 3rd digit as 3,5, or 9.  That's 3 ways.
Choose the 1st digit any of the remaining 5 digits.
Choose the 2nd digit any of the remaining 4 digits.:

3󬊄 = 60

d)how many digits in (b) are greater than 500?
Choose the 1st digit as 5, 6, 8 or 9. That's 4 ways.
Choose the 2nd digit any of the 6 digits.
Choose the 3rd digit any of the 6 digits.:

4󬝲 = 144

Edwin