general Maths Puzzle

Out of a box that contains 4 black and 6 white balls, three are randomly chosen. What is the
probability that all three will be black?

Read Solution (Total 3)

general Other Question

How many pairs of natural numbers are there so that difference of their squares is 60 ? A Four digit safe code does not contain the digits 1 and 4 at all. What is the
probability that it has at least one even digit?