A person invests Tk. 5508 in 4% stock at 102. He afterwards sells out at 105 and reinvests in 5% stock at 126. What is the change in his income?

Number of shares purchased = 5508/102
= 54.

Income from each share = 4% of Tk. 100
= Tk. 4

∴ Original income = Tk. (54 × 4) = Tk. 216

Money incurred from sale of share = Tk. (105 × 54)
= Tk. 5670

Number of new shares purchased = 5670/126 = 45

New income = Tk. (45 × 5)
= Tk. 225

∴ Change in income = Tk. (225 - 216)
= Tk. 9.