2 yellow marbles, 7 red marbles, 1 green marble.....total of 10 marbles
probability of first picking a yellow marble : 2/10 reduces to 1/5 replacing the marble probability of picking another yellow marble : 2/10 reduces to 1/5
The rate of motion is defined as the quotient between the distance covered (in our case 16 feet) divided by the time it took to cover that distance (in our case 8 minutes)