Mathematics - Probability Question with Solution | TestHub

MathematicsProbabilityConditional probabilityEasy2 minPYQ_2025

MathematicsEasynumerical

A card from a pack of 52 cards is lost. From the remaining 51 cards, $n$ cards are drawn and are found to be spades. If the probability of the lost card to be a spade is $\frac{11}{50}$ , the n is equal to

Answer:

2.00

Solution:

n cards are drawn \& are found all spade, thus remaining spades $= 13 - x$ remaining total cards $= 52 - x$
Now given that $P ($ lost card is spade $) = \frac{11}{50}$
$i.e. \frac{^{13 - n} C _{1}}{^{52 - n} C _{1}} = \frac{11}{50} 50 (13 - n) = 11 (52 - n) 39 n = 78 n = 2$

Stream:JEESubject:MathematicsTopic:ProbabilitySubtopic:Conditional probability

⏱ 2mℹ️ Source: PYQ_2025

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