Subject: General Aptitude · Chapter: Volume and Surface Area · Exam: · Marks: · Difficulty:
How much cardboard will it take to make an open cubical box with no top? I. The area of the bottom of the box is 4 square meters. II. The volume of the box is 8 cubic metres.
Answer
SELF-PRACTICE — the source book printed no answer.
Nothing is invented here, so this question has no answer on record.
Explanation
I. Let the length of each edge of the box be $a$ metres. Then, $a^{2}=4 \Rightarrow a=2 \mathrm{m}$. $\therefore$ Area of the cardboard needed $=5 a^{2}=\left(5 \times 2^{2}\right) \mathrm{m}^{2}=20 \mathrm{m}^{2}$. Thus, I alone gives the answer. II. $a^{3}=8 \Rightarrow a=2 \mathrm{m}$. $\therefore$ Required area $=5 a^{2}=\left(5 \times 2^{2}\right) \mathrm{m}^{2}=20 \mathrm{m}^{2}$. Thus, II alone gives the answer. So, correct answer is (c).