Question

A metal pipe 3m long was found to weight 7.6kg. What would be the weight of the same kind of 7.8m long pipe?

Answer 1

Given, the weight of 3m long pipe = 7.6kg

Using unitary method in which first we find the value of one unit and then the value of the required number of units.
$\therefore$ Weight of 1m long pipe = $\frac{7.6}{3}$kg
$\therefore$ Weight of 7.8m long pipe = $\frac{7.6}{3}\times 7.8$
= $19.76$kg
Hence, the weight of 7.8m long pipe is 19.76kg.