you choose a marble at random from a bag containing 10 red marbles, 5 yellow marbles, and 1 pink marble. You replace the marble and then choose again. Find the probability of P(both red)

red marbles = 10 yellow marbles = 5 pink marbles = 1 total marbles = red + yellow + pink = 10 + 5 + 1 = 16 probability of red marble (1st pick) = 10/16 probability of red marble (2nd pick with replacement) = 10/16 probability of both red = \frac{10}{16}\cdot\frac{10}{16}=\frac{100}{256}=\frac{25}{64}