Question

Find the probability of an event which is irrational among values of cosine of angles 0,30,45,60 and 90
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Answer 1

cos 0 is 1

cos 30 is √3/2

cos 45 is 1/√2

cos 60 is 1/2

cos 90 is 0

As you know that √2 and √3 are irrational numbers.

so, total no. of possible outcomes are 2

and total no. of outcomes are 5

This the probability to get irrational among values of cosine of angles 0, 30, 45, 60 and 90 is 2/5.