If the letters of the word 'PROBABILITY' are written down at random in a row, then probability that two B's are together, is
A.
Total number of ways in which the letters of the word 'PROBABILITY' can be arranged in a row
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Number of ways in which two B's are together
=
Required probability
=
A fair coin is tossed-at a fixed number of times. If the probability of getting exactly 3 heads equals the probability of getting exactly 5 heads, then the probability of getting exactly one head is
1/64
1/32
1/16
1/8
A person goes to office by car, scooter, bus and train, probability of which are 1/7, 3/7, 2/7 and 1/7, respectively. Probability that he reaches office late, if he takes car, scooter, bus or train is 2/9, 1/9, 4/9, and 1/9, respectively. Given that he reached office in time, the probability that he travelled by a car, is
1/7
2/7
3/7
4/7
Ram is visiting a friend. Ram knows that his friend has 2 children and 1 of them is a boy. Assuming that a child is equally likely to be a boy or a girl, then the probability that the other child is a girl, is
1/2
1/3
2/3
7/10
Out of 7 consonants and 4 vowels, the number of words (not necessarily meaningful) that can be made, each consisting of 3 consonants and 2 vowels is,
24800
25100
25200
25400
A fair six-faced die is rolled 12 times. The probability that each face turns up twice is equal to
A poker hand consists of 5 cards drawn at random from a well-shuffled pack of 52 cards. Then, the probability that a poker hand consists of a pair and a triple of equal face values (for example, 2 sevens and 3 kings or 2 aces and 3 queens, etc.) is
Each of a and b can take values 1 or 2 with equal probability. The probability that the equation ax2 + bx + 1= 0 has real roots, is equal to
Cards are drawn one-by-one without replacement from a well shuffled pack of 52 cards. Then, the probability that a face card (jack, queen or king) will appear for the first time on the third turn is equal to
There are two coins, one unbiased with probaility or getting heads and the other one is biased with probability of getting heads. A coin is selected at random and tossed. It shows heads up. Then, the probability that the unbiased coin was selected is