What will be the change in income when multiplier is 3 and increase in investment is Rs 20 crore?

60 crore

Investment multiplier refers to the increase in the aggregate income of the economy as a result of an increase in the investments done by the government.  The ratio of ΔY to ΔI is called the investment multiplier.

K = \(\frac{ΔY}{ΔI}\)

3 = \(\frac{ΔY}{\text{20 crore}}\)

ΔY = 20 crore * 3

ΔY = 60 crore