In the 1st case-
No of shares =360
N.V of 1 share =Rs.10
Rate of dividend =12
∴Income on 1 share =12 of 10 =12100×10=Rs.1.2
⇒Total income=360×1.2=Rs.432
Now he sell all the shares for Rs.21 each
∴Money obtained by selling all the 360 shares=360×21=Rs.7560
In the 2nd case-
Sum invested =Rs.7560
N.V of 1 share =Rs.5
Rate of dividend =4.5%
M.V of 1 share =Rs.3.50
∴No. of share=75603.50=2160
Dividend on 1 share =4.5% of Rs. 5 =4.5100×5=Rs .225
⇒Total income=2160×.225=Rs.486
∴Change in income=Rs.486−Rs.432=Rs.54