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Chapter 18: Problem 734
The average marks of boys in a class is 50 and that of girls is 40 . The average marks of boys and girls combined is 48 . The percentage of boys in the class is (a) 75 (b) 80 (c) 60 (d) 55
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A and B throws a dice. The probability that A wins, if he throws a number higher than \(\mathrm{B}\) is (a) \((1 / 2)\) (b) \((15 / 36)\) (c) \((1 / 36)\) (d) None
Three identical dice are rolled. The probability that the same number will appear on each of them is (a) \((1 / 6)\) (b) \((1 / 36)\) (c) \((1 / 216)\) (d) \((1 / 18)\)
The probability of having at least one tail in 4 throws with a coin is (a) \((15 / 16)\) (b) \((1 / 16)\) (c) \((1 / 4)\) (d) \((1 / 8)\)
A fair dice is thrown 20 Times. The probability that on the tenth throw the fourth six appear is (a) \(\left[\left\\{\left({ }^{20}{ }_{10}\right) \cdot 5^{6}\right\\} / 6^{20}\right]\) (b) \(\left[\left(120 \times 5^{7}\right) / 6^{10}\right]\) (c) \(\left[\left(84 \times 5^{6}\right) / 6^{10}\right]\) (d) None
The mean and standard deviation of \(\mathrm{x}\) is 40 and 4 respectively the mean and standard deviation of \([(x-40) / 4]\) is (a) 1,0 (b) 1,1 (c) 0,1 (d) \(0,-1\)
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