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If the sum of the length, breadth and height of a rectangular parallelopiped is 24 cm and the length of its diagonal is 15 cm, then its total surface area is
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- 256 cm²
- 265 cm²
- 315 cm²
- 351 cm²
- 256 cm²
Correct Option: D
l + b + h = 24 [given]
l² + b² + h² = 225 [given]
∴ (l + b + h)²
= l² + b² + h² + 2(lb + bh + hl)
⇒ (24)² = 225 + 2 (lb + bh + hl)
⇒ 2(lb + bh + hl)
= 576 – 225 = 351 sq. cm.
