If ^@(p, p)^@ is the solution of equations ^@ax + by + (t - s) = 0^@ and ^@bx + ay + (s - r) = 0 (a \ne b)^@ then, which of the following must be true?
AB and AC are two chords of a circle such that AB = 2AC. If distances of AB and AC from the centre are 3 cm and 4 cm respectively, find the area of circle. (Assume π = 3)
A box contains 5 orange and 7 black balls. Hameeda takes out a ball, puts it back, and then takes out another ball. What is the probability that both balls were orange?