The sum of length, breadth and height of a cuboid is 19 cm and its diagonal is

(c) 236 cm2
Let l, b and h be the length, breadth and height of the cuboid.
Then,

$l+b+h=19$

$\Rightarrow(l+b+h)^{2}=(19)^{2}$

Therefore,

$\left(l^{2}+b^{2}+h^{2}\right)+2(l b+b h+l h)=361$

$\Rightarrow(5 \sqrt{5})^{2}+2(l b+b h+l h)=361$

$\Rightarrow 2(l b+b h+l h)=(361-125)$

$\Rightarrow 2(l b+b h+l h)=236 \mathrm{~cm}^{2}$

Hence, the surface area of the cuboid is $236 \mathrm{~cm}^{2}$.