ok! these are realy really hard, so please help me!
1) intergers a,b,c, and d, not necessarily distinct, are chosen independently and at random from 0 to 2007, inclusive. What is the probability that ad-bc is even?
2) How many three-digit numbers are composed of three distinct digits such that one digit is the average of the other two?
p.s. i have the answers, but not the how or the why, so please make sure that your answers are actually correct, because last time most of the answers i received were wrong, thanks ^^
answer 1: 5/8 answer 2: 112
but i really don't know how to do these! the answers were given to me because it was a multiply choice thing and i was told the correct ones after the test. ^^ HELP!
2007-03-30
19:05:37
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8 answers
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asked by
cherritown
2
in
Mathematics