6 boys and 6 girls sit in a row at random. Find the probability that all the girls sit together.

A ordinary cube has four plane faces, one face marked 2 and another face marked 3, find the probability of getting a total of 7 in 5 throws.

Three numbers are chosen from 1 to 20. Find the probability that they are consecutive.

If A and B are two independent events such that P(A) = 0.3 and . Find P(B).

An unbiased die with face marked 1, 2, 3, 4, 5, 6 is rolled four times. Out of 4 face values obtained, find the probability that the minimum face value is not less than 2 and the maximum face value is not greater than 5.