Subject: General Aptitude · Chapter: Area · Exam: · Marks: · Difficulty:
If the side of a square is increased by 5 cm, the area increases by 165 sq. cm. The side of the square is
(a)12 cm
(b)13 cm
(c)14 cm
(d)15 cm
Answer
Answer (as printed): C
Explanation
Let original side $=x \mathrm{cm}$. Then, new side $=(x+5) \mathrm{cm}$. $\therefore(x+5)^{2}-x^{2}=165 \Leftrightarrow x^{2}+10 x+25-x^{2}=165$ $$\Leftrightarrow 10 x=140 \Leftrightarrow x=14 .$$ Hence, the side of the square is 14 cm .