important question from the book -ML aggarwal( avichal publication)class 10th , chapter3, shares and dividends

we have given that A man bought 360 ten-rupee shares of a company paying 12 percent per annum.

He sold the shares when their price rose to Rs. 21 per share and invested the proceeds in five-rupee shares paying 4.5 per cent per annum at Rs. 3.50 per share.

kinldy please explain it how to Find the annual changes in his income.

Q no. 25, exercise 3, ML Publication, share and dividends

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 =10012×10=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=3.507560=2160

Dividend on 1 share =4.5% of Rs. 5 =1004.5×5=Rs .225

⇒Total income=2160×.225=Rs.486

∴Change in income=Rs.486−Rs.432=Rs.54