Question

Radhika's junk shop's rate list is given below:
$\begin{array}{cc}\text{Item}& \text{Price per kg}\\ \text{Newspaper}& \text{₹6}\\ \text{Brass}& \text{₹280}\\ \text{Iron}& \text{₹23}\\ \text{Copper}& \text{₹402}\\ \text{Aluminium}& \text{₹120}\end{array}$

What is the approximate price of 19 kg of copper?

Answer 1

Price of 1 kg of copper = ₹402
Price of 19 kg copper = ₹402 x 19

₹402 can be rounded off as ₹400
and 19 kg can be rounded off as 20
Thus, appoximate total cost of 19 kg copper can be rounded off as: ₹400 x 20 = ₹8000