Which is the better stock, 5% at 143 or 3 1/ 2% at 93?

Let investment in each case be Rs. (143 x 93)
Income from 5% stock = Rs. (5 / 143) x 143 x 93 = Rs. 465
Income from 3¹/₂% stock = Rs. (3.5 / 93) x 143 x 93 = Rs. 500.50
∴ 3¹/₂% stock at 93 is better.