11 Views

Question : If the sum of the length, breadth and height of a rectangular parallelepiped is 24 cm and the length of its diagonal is 15 cm, then its total surface area is:

Option 1: 256 cm2

Option 2: 265 cm2

Option 3: 315 cm2

Option 4: 351 cm2


Team Careers360 1st Jan, 2024
Answer (1)
Team Careers360 11th Jan, 2024

Correct Answer: 351 cm 2


Solution : Given: The sum of the length, breadth and height of a rectangular parallelepiped is 24 cm and the length of its diagonal is 15 cm.
Let $l,b,$ and $h$ be the length, breadth and height of the rectangular parallelepiped.
Total surface area = $2(lb+bh+hl)$
Length of diagonal = $\sqrt{l^2+b^2+h^2}$
According to the question,
$\sqrt{l^2+b^2+h^2}=15$
$⇒(l^2+b^2+h^2) = 225$
Also, ($l+b+h$) = 24
$⇒(l+b+h)^2 = 24^2$
$⇒l^2+b^2+h^2+2 (lb+bh+hl) = 576$
$\therefore 2(lb+bh+hl)=576 - 225=351$ cm 2
Hence, the correct answer is 351 cm 2 .

Know More About

Related Questions

TOEFL ® Registrations 2024
Apply
Accepted by more than 11,000 universities in over 150 countries worldwide
Manipal Online M.Com Admissions
Apply
Apply for Online M.Com from Manipal University
View All Application Forms

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students
30,000+ Colleges
500+ Exams
1500+ E-books