Question 359527: what is the probability that an integer from 1 to 10000 is divisible by 10 or 15
Answer by Fombitz(32388)   (Show Source):
You can put this solution on YOUR website! Look at the numbers divisible by 10.
{10,20,30,40,50,...,9990,10000)- there are 1000 of them.
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Look at the numbers divisible by 15.
{15,30,45,60,75,...,9990) - there are 666 of them.
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Then look at the ones that are divisble by both 10 and 15.
{30,60,90,...,9990) - there are 333 of them, you don't want to double count those.
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P(10 or 15)=P(10)+P(15)-P(both)
P(10 or 15)=
P(10 or 15)=
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