• Kiran bought 1 kg plastic for Rs 10, but sold 1 kg plastic for Rs 12. How much money does she earn on selling 1 kg plastic? Rs _______
So, how much money does she earn for 63 kg? Rs _______

Cost price of 1 kg plastic = Rs 10
Selling price of 1 kg plastic = Rs 12
Profit on selling 1 kg plastic = Rs (12 − 10)
= Rs 2
Profit on selling 63 kg plastic = Rs 2 × 63
= Rs 126

We do it in the following manner:
2 × 60 = 120
2 × 3 = 6

$$\begin{gathered} \begin{array}{ccc}1& 2& 0\\ +& & 6\end{array} \\ \underline{\overline{\begin{array}{ccc}1& 2& 6\end{array}}} \end{gathered}$$

Hence, Kiran will earn Rs 126 on selling 63 kg plastic.