FIFTY POINTS

y=-16t^2+40t+2

For what interval or intervals of time will the projectile be
above 18 feet?
a.) Between 1 and 1.5 seconds
b.) Less than 1 second and greater than 1.5 seconds
c.) Between 0.5 and 2 seconds
d.) Less than 0.5 second and greater than 2 seconds