one cake is a rectangular with a length of 14 inches,a width of 9 inches, and a height of 3 inches. the other is a round cake with radius of 5 inches and a height of 4 inches. which cake do you prefer to buy if they cost the same price? why?

Ans:
For the same price, you would obviously like to get *more* cake, right?
So let us find out the volumes of both the cakes.

Volume of 1st cake - rectangular = length * width * height 
= 

Volume of 2nd cake - cylindrical = base area * height
= 

Clearly the first cake is bigger and a better buy, for the same cost.

Hope you got it :)