One bag contains 3 red and 5 black balls. Another bag contains 6 red and 4 black balls. A ball is transferred from first bag to the second bag and then a ball is drawn from the second bag. Find the probability that the ball drawn is red.
Prove that if E and F are independent events, then the events E and F' are also independent.
If A and B are square matrices of order 3 such that |A| = –1, |B| = 3, then find the value of |2AB|.
Obtain the differential equation of the family of circles passing through the points (a, 0) and (– a, 0).