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Formula
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Area of circle = πr²
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Find Area of circle
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Area of circle = 3.15 x 3²
Area of circle = 28.26 unit²
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Answer: Area = 28.16 unit²
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Irrational because it can not be written as a fraction
Answer: the diameter is 7cm And the radius is 3.5 cm
Step-by-step explanation:
The event that either M1 or M2 fails has probability

by the addition rule. Failure events are independent, so

so that

Denote this probability by
. Then
follows a geometric distribution with this parameter
and has density

The expectation is
.