Ratio and Rate

1) Which is the lower rate: 630/h or 150 c.c./s ?
2) Given a rectangle of dimensions 3cm4cm. If this rectangle is a scale drawing to a scale of 1:250, find its actual area in ㎡.
3) A car is parked in a car-park from 7:45 a.m. to 4:30 p.m. on the same day. Find
a) the total time for which the car is parked,
b) the parking fee if the rate of charges is $12.5 for the first hour and $5 for each half hour or part of a half hour thereof.