The working of multiplier can be explained as follows:We are given that the value of MPC $=0.8$ and also that initial increase in investment is $\text{₹} 800$ crore. This implies that with every increase of $\text{₹} 1$ in the income, people consume 0.8 part of the increased income i.e, ., people consume $\text{₹} 0.80$and Save ₹ 0.20. The table shows that initial increase in investment of $\text{₹} 800$ will lead to a change in income by $\text{₹} 800$ in the first round. As MPC is 0.8 , so people will consume 0.8 of the increased income (i.e. $\text{₹} 640$ ), thereby saving $\text{₹} 160$. This will be termed as leakage (as it is not ploughed back into the economy). In the next round, due to the increase in the consumption expenditure by $\text{₹} 640$, there will be an increase in income $\text{₹} 640$. The people will again spend the increased income i.e. $\text{₹} 512$ and save the rest part of the income $\text{₹} 128$. In the third round, similarly the increased consumption expenditure of $\text{₹} 512$ will cause a change in the income by $\text{₹} 512$. They will spend a part of this income on consumption i.e., $\text{₹} 409.6$ and will save the rest of the increased income $\text{₹} 102.4$. This process will continue and the income will go on increasing as a result of increase in consumption. The total change $(\Delta Y)=\text{₹} 4000$ (approx) and the change in the investment $(\Delta I)$ will be 800 . $k\;=\;\frac{1}{1- MPC}$ $\;=\;\frac{\Delta Y}{\Delta I}$ $k\;=\;\frac{1}{1-0.8}$ $=\;\frac{\Delta Y}{800}$ or, $\;\frac{1}{0.2}=\;\frac{\Delta Y}{800}$ So, $\Delta Y=4,000$ Thus, we can observe that an initial increase in the investment by $\text{₹} 800$ crore results in increase of income and output by ₹ 4000 crore.