The area of a rectangular field is equal to 200 square meters. Its perimeter is equal to 60 meters. Find the width of this rectangle.
Choose the correct choice from the following answers.
A) 5
B) 10
C) 15
D) 20
E) 25

Rationale: "l * w = 200 : area , l is the length and w is the width . 2 l + 2 w = 60 : perimeter l = 30 - w : solve for l ( 30 - w ) * w = 200 : substitute in the area equation w = 10 and l = 20 : correct answer b"
Answer: B