There are 60 students in a speech contest. Yesterday, 1/3 of them gave their speeches. Today, 4/5 of the remaining students gave their speeches. How many students still haven't given their speeches?

Y=4x^2+x-1 solve using quadratic formula

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

An objects motion is described by the equation d= 4sin (pi t) what will the height of the object be at 1.75 seconds?