20 x 42= 840
So the area would be 840 mm^2.
Given :
A 18-mile taxi ride takes 21 minutes and costs $12.60.
To Find :
The cost of a 39- mile taxi ride. What unit price do you need.
Solution :
Unit price per mile :

Cost of 39 mile taxi ride :

Therefore, unit price is $27.3 and unit price is $0.7 / mile .
Hence, this is the required solution.
15r means that she burns 15 calories per min, for as many mins as she ran. EG: if she ran for 10 min, then she burned 150 cals. The other one I'm not so sure.
There would be 8 pickup trucks in the parking lot.