Seven Star Limited Company currently pays a dividend of Rs$.10$ per share and has a share using a discount rate of $15$ percent. price of Rs$.200.$

a$.$ If this dividend was expected to grow at a $12$ percent rate forever, what is the firm's expected, or required, return on equity using a dividend discount model approach?

b$.$ Instead of the situation in Part $($a$),$ suppose that the dividend was expected to grow at a $20$ percent rate for five years and at $10$ percent per year thereafter. Now what is the firm's expected, or required, return on equity?