A dice is thrown repeatedly till two successive 4′s are obtained then find the probability this process stops at 5th throw (A) 6575 (B) 65125 (C) 65175 (D) 6535
Five persons entered the lift cabin on the ground floor of an eight-floor house. Suppose that each of them, independently and with equal probability, can leave the cabin at any floor beginning with the first. Find out the probability of all five persons leaving at different floors.
There are n letters and n addressed envelopes. Find the probability that all the letters are not kept in the right envelope.
If the probability of a six-digit number N whose six digits are 1, 2, 3, 4, 5, 6 written as random order is divisible by 6 is p, then the value of 1/p is _______.
There are some experiment in which the outcomes cannot be identified discretely. For example, an ellipse of eccentricity 22/3 is inscribed in a circle and a point within the circle is chosen at random. Now, we want to find the probability that this point lies outside the ellipse. Then, the point must lie in the shaded region shown in Figure. Let the radius of the circle be a and length of minor axis of the ellipse be 2b. Given that
Then, the area of circle serves as sample space and area of the shaded region represents the area for favorable cases. Then, required probability is
p=Area of circleArea of shaded region
Now, answer the following questions.
A point is selected at random inside a circle. The probability that the point is closer to the center of the circle than to its circumference is
A composite number is selected at random from the first 30 natural numbers and it is divided by 5. The probability that there will be a remainder is
A four figure number is formed of the figure 1, 2, 3, 5 with no repetition. The probability that the number is divisible by 5 is
A shoping mall is running a scheme: Each packet of detergent SURF contains a coupon which bears letter of the word SURF, if a person buys at least four packets of detergent SURF, and produce all the letters of the word SURF, then he gets one free packet of detergent.
If a person buys 8 such packets at a time, then the number of different combinations of coupon he has is