JR Computers, a firm that manufactures and sell personal computers is an all$-$equity firm with $100,000$ shares outstanding, $$10$ million in earnings after taxes and a market value of $$150$ million. Assume that this firm borrows $$60$ million at an interest rate of $8\%$ and buys back $40,000$ shares, using the funds. If the firm$$s tax rate is $50\%$ estimate

$($a$)$ the effect on earnings per share of the action.

$($b$)$ What should the interest rate on the debt be for the earnings per share effect to disappear.