Write a unit rate for the situation 2520 kilobytes in 18 seconds

(P. S. please help)

Me! 50 points! why does when we come home, our door is unlocked and there is grease on the door knob, me solve this , and i don't know what category this goes under

One card is dealt from a 52 card deck. find the probability that the dealt card is a 4 or a black 7

Asquare picture with sides of 32 inches is to be mounted on a square mat with sides of 52 inches. find the area of the mat that will remain uncovered by the picture.