PSAT #1, Section 4, #25

You’re told that the length of the garden is 9 feet less than 3 times the width, so you need to translate that into math:

l = 3w – 9

Once you’ve done that, you can solve for the width and length because you know that the area (AKA: lw) is 5,670 square feet.


Because this is the calculator section, I wouldn’t waste much time trying to factor that. I’d just use my calculator (either graphing or a quadratic formula program) to see that the positive solution for w is 45 feet!

If w = 45 feet, then l = 3(45) – 9 = 126 feet. The perimeter of the garden, then, is 2(45) + 2(126) = 342 feet.


Leave a Reply