Question
An unbiased coin is tossed until a head appears. The
expected number of tosses required isSolution
Let X denote the number of tails tossed before the head appears. Then X is a geometric random variable. P(head) = 1 / 2 and the expectation is E(X)=1 / (1/2) = 2.
A shopkeeper bought an article for Rs 800 and sold it for Rs 960. Find the profit and the profit percentage.
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A chair listed at 550 is available at successive discounts of 25% and 10%. The selling price of the chair is
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