A box contains 9 tickets numbered 1 to 9 inclusive. If 3 tickets are drawn from the box one at a time, the probability that they are alternatively either {odd, even, odd} or {even, odd, even}is:

• $\frac{5}{17}$

• $\frac{4}{17}$

• $\frac{5}{16}$

• $\frac{5}{18}$

If $\mathrm{P}\left(\mathrm{A}\right) = \frac{1}{12}, \mathrm{P}\left(\mathrm{B}\right) = \frac{5}{12} \mathrm{and} \mathrm{P}\left(\frac{\mathrm{B}}{\mathrm{A}}\right) = \frac{1}{15}$, then P(A $\cup$ B) is equal to :

• $\frac{89}{180}$

• $\frac{90}{180}$

• $\frac{91}{180}$

• $\frac{92}{180}$

A bag contains 3 black and 4 white balls. Two balls are drawn one by one at random without replacement. The probability that the second drawn ball is white, is

• $\frac{4}{49}$

• $\frac{1}{7}$

• $\frac{4}{7}$

• $\frac{12}{49}$

A coin is tossed 4 times. The probability that atleast one head turns up 1s

• $\frac{1}{16}$

• $\frac{2}{16}$

• $\frac{14}{16}$

• $\frac{15}{16}$

A speaks truth in 75% cases and B speaks truth in 80% cases, The probability that they contradict each other in a statement, is

• $\frac{7}{20}$

• $\frac{13}{20}$

• $\frac{3}{5}$

• $\frac{2}{5}$

The probability that a leap year will have 53 Friday or 53 Saturday, is

• $\frac{2}{7}$

• $\frac{3}{7}$

• $\frac{4}{7}$

• $\frac{1}{7}$

Ten coins are thrown simultaneously, the probability of getting atleast 7 heads is

• $\frac{63}{256}$

• $\frac{121}{172}$

• $\frac{113}{512}$

• $\frac{11}{64}$

If four digits are taken fromthe digits 1, 2, 3, 4, 5, 6, 7. The probability that the sum of digits is less than 12, is

• $\frac{3}{35}$

• $\frac{4}{35}$

• $\frac{2}{35}$

• $\frac{1}{35}$

49.

The probability of happening exactly one of the two events A and B is

• $\mathrm{P}\left(\mathrm{A}\right) + \mathrm{P}\left(\mathrm{B}\right) - 2\mathrm{P}\left(\mathrm{A} \cap \mathrm{B}\right)$

• $\mathrm{P}\left(\mathrm{A}\right) + \mathrm{P}\left(\mathrm{B}\right) - \mathrm{P}\left(\mathrm{A} \cap \mathrm{B}\right)$

• P(A) - P(B)

• None of the above

In a throw of two dice, the probability of getting a sum of 7 or 11 is

• $\frac{2}{9}$

• $\frac{7}{9}$

• $\frac{5}{9}$

• None of these