Pupils in a class were asked how they travel to school. The results were recorded in the table below.
Car
13
Bus
6
Train
5
Walk
8
If a pupil in the class was picked at random, what is the probability
that one of them walked to school as a percentage?

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).