The king, queen and jack of clubs are removed from a deck of 52 playing cards and then shuffled. A card is
drawn from the remaining cards. Find the probability of
getting:
(i) a heart
(ii) a queen
(iii) a club
(iv) '9' of red color

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).