ExamBro
ExamBro
JEE Advanced · Mathematics · 25. AOD

A rectangular sheet of fixed perimeter with sides having their lengths in the ratio 8:15 is converted into an open rectangular box by folding after removing squares of equal area from all four corners. If the total area of removed squares is 100, the resulting box has maximum volume. Then the lengths of the sides of the rectangular sheet are:

  1. A 24
  2. B 32
  3. C 45
  4. D 60
Verified Solution

Answer & Solution

Correct Answer

(C) 45

Step-by-step Solution

Detailed explanation



Let l = 8x,b = 15x
Volume=8x-2a15x-2aa=4a3-46a2x+120ax2
dVda = 6a2-46ax+60x2
dVdaat a = 5 = 0
x = 3 and 56
d2Vda2 = 6a-23x
d2Vda2at a = 5&x = 3<0
So, at x=3, it gives maxima:
d2Vda2at a = 5&x = 56>0
So, at x = 5 6 , it gives minima.
So by x=3 (for max volume):
8x = 24, 15x = 45
Same subject
Explore more questions on app
From JEE Advanced
Explore more questions on app