By selling an article for ₹ 24, a man gains as much percent as its cost price. Find the cost price of the article.

Rajat invested ₹ 24,000 in 7% hundred rupee shares at 20% discount. After one year, he sold these shares at ₹ 75 each and invested the proceeds (including dividend of first year) in 18% twenty five rupee shares at 64% premium. Find :

(i) his gain or loss after one year.

(ii) his annual income from the second investment.

(iii) the percentage of increase in return on his original investment.

A man sold some ₹ 20 shares, paying 8% dividend, at 10% discount and invested the proceeds in ₹ 10 shares, paying 12% dividend, at 50% premium. If the change in his annual income is ₹ 600, find the number of shares sold by the man.