I am having trouble with these questions. please help out with explanations

With the clean decomposition of variance in the framework of a single index model, we have discussed various relationships among rho (the correlation coefficienth, the beta, the market return standard deviation, the systematic risk, the individual stock standard deviation representing, total risk, and the firm-specific standard deviation. Suppose for stock]H, the standard deviation representing its total risk is 50%, the standard deviation of market return is 20%, and the standard deviation representing J. H's firm specific risk is 30\%. What is Jit's correlation coefficient with the market return? 0.60 0.40 0.30 0.80 With the clean decomposition of variance in the framework of a single index model, we have discussed various relationships among rho (the correlation coefficient, the beta, the market return standard deviation, the systematic risk, the individual stock standard deviation representing total risk, and the firm-specific standard deviation. Suppose for stock ABC, the standard deviation representing its firm specific risk is 30%, and the standard deviation representing its total risk is 50%, what is the standard deviation representing its systematic risk? 40% 50% 30% 20% With the clean decomposition of variance in the framework of a single index model, we have discussed various relationships among rho (the correlation coefficienth, the beta, the market return standard deviation, the systematic risk, the individual stock standard deviation representing total risk, and the firm-specific standard deviation, Suppose for stock ABC, the standard deviation representing its firm specific risk is 30%, the standard deviation representing its total risk is 50%, and the standard deviation of market return is 20%. What is ABC, beta? 2.0 1.5 1.0 0.5