Question 667806: a piggy-bank contains a certain number of coins. of which, 53 are dimes and 19 are nickels. the remainder of the coins are quarters. if the probability of selecting a quarter from this bank is 1/4, how many quarters does the bank contain?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! a piggy-bank contains a certain number of coins. of which, 53 are dimes and 19 are nickels. the remainder of the coins are quarters. if the probability of selecting a quarter from this bank is 1/4, how many quarters does the bank contain?
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Let "q" be the number of quarters.
P(pick a quarter) = q/(53+19+q) = 1/4
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q/(72+q) = 1/4
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72+q = 4q
3q = 72
q = 24 (# of quarters)
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Cheers,
Stan H.
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