SOLUTION: ow many​ 7-digit telephone numbers are possible if the first digit cannot be six and ​(a) only even digits may be​ used? ​(b) the number must be a multiple of 10​ (tha

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Question 1160041: ow many​ 7-digit telephone numbers are possible if the first digit cannot be six and
​(a) only even digits may be​ used?
​(b) the number must be a multiple of 10​ (that is, it must end in​ 0)?
​(c) the number must be a multiple of 1 comma 000​?
​(d) the first 3 digits are 192​?
​(e) no repetitions are​ allowed?

Answer by Boreal(15235)   (Show Source): You can put this solution on YOUR website!
a. Even digits are 2,4,6,8,0.
4 ways to choose the first*5^6=62,500
b. then there are 10^6 or 1 million.
c. then there are 10^4 or 10,000
d. then there are also 10^4 or 10,000
e. 10*9*8*7*6*5*4=604,800

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