The mathematics faculty at a college consists of 9 professors, 10 associate professors, 4 assistant professors, and 9 instructors. if one faculty member is randomly selected, find the probability of choosing a professor or an instructor.

This summer the number of tourists in salem increased 4.5% from last years total of 426000. how many more tourists came to salem this summer

Can someone show me step by step how to do this?

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).