What kind of number is negative 18/9

Shane can shovel the driveway in 4 hours, but if his sister it would take 2 hours. how long would it take taylor to shovel the driveway alone

If you had $1,900,000, how many days would it take you to spend all if you spent $1 a second. (there are 86,400 seconds in a day)

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.