Paul has 10 red and 10 blue marbles in a bag. How would he have to change the contents of
his bag, if he wants the probability of selecting a red
marble to be 1 3?

Amass weighing 16 pounds stretches a spring 8/3 feet. the mass is initially released from rest from a point 2 feet below the equilibrium position, and the subsequent motion takes place in a medium that offers a damping force that is numerically equal to 1/2 the instantaneous velocity. find the equation of motion if the mass is driven by an external force equal to f(t)=cos(2t).