$13-6.$ A rectangular block of length $l,$ width $w,$ and height $h$ floats in water as shown.

$($a$)$ What is the weight of the block?

$($b$)$ What is the density of the block?

$($c$)$ Calculate the weight and density of a block $25\mathrm{.}0$ cm long, $15\mathrm{.}0$ cm wide, and $11\mathrm{.}0$ cm high that floats with $9\mathrm{.}0$ cm of the block submerged.