Question 373471: A set consists of all the perfect squares less than 1000. what is the probability that a number chosen at random from this set is divisible by 4 or 5? explain.
Answer by fractalier(6550)   (Show Source):
You can put this solution on YOUR website! There are 31 squares less than 1000.
Every even number less than 31, when squared, gives a number divisible by four. Thus there are 15 of them.
Every number less than 31 that is divisible has its square also divisible by five...there are six of them.
However, 10, 20 and 30 squareds are divisible by 4 and 5 so that is duplicating...
So I would answer 15 + 6 - 3 = 18 out of 31
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