SOLUTION: An integer is chosen at random from the first 200 positive integers.If the integer chosen is divisible by 5, find the probability that it is even.

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Question 1135862: An integer is chosen at random from the first 200 positive integers.If the integer chosen is divisible by 5, find the probability that it is even.
Found 2 solutions by Alan3354, ikleyn:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
2 & 5 --> divisible by 10
----------------
20 of 200 ---> 0.1

Answer by ikleyn(52879) About Me  (Show Source):
You can put this solution on YOUR website!
.
Let N be the set of positive integers between 1 and 200, inclusively.

So, N contains exactly 200 elements.



Let F be the set of positive integers from 1 to 200 inclusively that are divisible by 5.


The number of such integers is  200%2F5 = 40;  so the number of elements in the set F is 40.



Of this set F, exactly HALF of its elements are even: in other words, in the set F 20 elements are even.



The problem asks: If the randomly chosen integer from N belongs to F, what is the probability that it is even.



Since exactly half of all elements of F are even, the answer to this question is obvious:  this probability is  1%2F2.

Answered and solved.