Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
Within a rectangular garden 10 m wide and 20 m long, we wish to pave a walk around the borders of uniform width so as to leave an area of $96 \mathrm{m}^{2}$ for flowers. How wide should the walk be?
(a)1 m
(b)2 m
(c)2.1 m
(d)2.5 m
Answer
Answer (as printed): B
Explanation
Let the width of walk be x metres. Then, (20 – 2x) (10 – 2x) = 96 ⇔ 4x2 + 60x – 104 = 0 ⇔ x2 + 15x – 26 = 0 ⇔ (x – 13) (x – 2) = 0 ⇔ x = 2 [\ x ≠ 13]
Explanation as extracted from the printed page; notation may be imperfect.