I am having difficulty solving for both B & C.

Eastern Electric currently pays a dividend of about $1.89 per share and sells for $36 a share.

a.If investors believe the growth rate of dividends is 3% per year, what rate of return do they expect to earn on the stock?(Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.)

I calculated 8.40%

b.If investors' required rate of return is 12%, what must be the growth rate they expect of the firm?(Do not round intermediate calculations. Enter your answer as a percent rounded to 2 decimal places.)

c.If the sustainable growth rate is 2% and the plowback ratio is 0.4, what must be the rate of return earned by the firm on its new investments?(Enter your answer as a percent rounded to 2 decimal places.)