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GATE 2017 ME (ME2) – Question 11

Engineering Mathematics · Complex Variables: Analytic functions, Cauchy-Riemann equations, integral theorem, Taylor and Laurent series · 1 mark · Numerical answer

Two coins are tossed simultaneously. The probability of getting at least one head, to two decimal places, is ______.

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Correct answer: 0.75 to 0.75

Explanation

The equally likely outcomes are HH, HT, TH and TT. Exactly three contain a head. Equivalently, subtract the probability of two tails from one: 1−(1/2)²=3/4=**0.75**. This counts two heads once rather than adding overlapping head events.