Question

How many planks each of which is 3 m long, 15 cm broad and 5 cm thick can be prepared from a wooden block 6 m long, 75 cm broad and 45 cm thick?

Answer 1

Length of wooden block (l) = 6 m
Width (b) = 75 cm = 0.75 m
Thickness (h)= 45 cm = 0.45 m
$\therefore$ Volume = $l\times b\times h=6\times 0.75\times 0.45m^3$
Length of plank (l)= 3 m
Breadth (b) = 15 cm = 0.15 m
Thickness (h) = 5 cm =0.05 m
$\therefore$ Volume = $3\times 0.15\times 0.05m^3$
Number of planks
= $\frac{6\times 0.75\times 0.45}{3\times 0.15\times 0.05}$= $\frac{6\times 75\times 45\times 100\times 100}{3\times 15\times 5\times 100\times 100}$
= 90