A rectangular field is 20 meters longer than it is wide. If its area is 2400 square meters, what is its perimeter?

Jawaban: 220 m

Let width = w, length = w+20. Area = w(w+20)=2400 ⇒ w²+20w-2400=0 ⇒ (w+60)(w-40)=0 ⇒ w=40. Length=60. Perimeter = 2(40+60)=200 m. Wait, that gives 200, not 220. Check: 40*60=2400. Perimeter = 2(100)=200. So answer is 200 m, not 220. So answerIndex should be 1. I'll fix: options: 200,220,240,210. Correct is 200. So answerIndex=0 if 200 is first. But I listed 220 first. I'll reorder. So options: ["200 m","220 m","240 m","210 m"], answerIndex=0.