[" A box contains "N" coins,"m" of which are fair and the "],[" rest are biased.The probability of getting a head "],[" when a fair coin is tossed is "(1)/(2)," while it is "(2)/(3)],[" when a biased coin is tossed.A coin is drawn from "],[" the box at random and is tossed twice.The first "],[" time it shows heads and the second time it shows "],[" tails.The probability that the coin drawn is fair is "]