A printed page is to have total area of 80 sq.cm with margin of 1 cm at the top and on each side and margin of 1.5 cm at the bottom. Which of the following are true?
(A) Area of printed portion; $A= (x-2) \left(y-\frac{5}{2}\right)$
(B) Printed area is maximum at $x= 18 \, cm $
(C) Printed Area function $A(x)= 85-\frac{5x}{2}-\frac{160}{x}$
(D) Printed area is maximum at y = 8 cm
(E) Dimension of printed page are 10 cm & 8 cm
Choose the correct answer from the options given below :
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A), (C), (E) only
Area of the pointed portion, $A=(x-2)(y-2.5)$
and,
$x×y=80$
$⇒y=\frac{80}{x}$
$A=(x-2)\left(\frac{80}{x}-2.5\right)=\frac{(x-2)(80-2.5x)}{x}$
∴ (A), (C), (E) only