The length breadth and height of a cuboid are in the ratio 7 5 3 and its whole surface area is 27832...........

Explanation:

Let, length = 7x cm, breadth = 5x cm and height = 3x cm 
Whole surface area = 2(lb + bh + lh) = 2(7x × 5x + 5x × 3x + 7x × 3x) cm² = (142 x²) cm² 
142 x² = 27832 => x² = 196 => x = √196 = 14 cm
l = 14 × 7 = 98 cm
b = 14 × 5 = 70 cm
h = 14 × 3 = 42 cm 
Volume (l × b × h) = (98 × 70 × 42) cm³ = 288120 cm³