A farmer has two rectangular fields. The larger has twice the length and four times the width of the smaller field. If the smaller field has area k, then the area of the larger field is greater than the area of the smaller field by what amount?

Correct Answer: 7k
Let the length and width of the smaller field be L & W respectively. Area of the smaller field,  k = L x W Area of the larger field = 2L x 4W = 8(L x W) = 8k. So, the area of the larger field is larger by (8k - k) = 7k than the smaller field.