Question

In the 3-month period November 1, 2014, through January 31, 2015, Hess Corp. (HES) stock decreased from $80 to $64 per share, and Exxon Mobil (XOM) stock decreased from $96 to $80 per share.† If you invested a total of $25,920 in these stocks at the beginning of November and sold them for $21,120 3 months later, how many shares of each stock did you buy?

Answer 1

Let we bought shares of Hess Corp. and shares of Exxon Mobil.

Now, at the beginning of November we invested total and values of shares are and for HES and XOM.

So    (1)

Similarly, at the end of 3 months, my values of investment reduced to and values of shares are and .

So,    (2)

Now we solve equation (1) and (2).

Divide equation (1) and (2) by 16 both sides, we get

(3)

(4)

Now multiply eq. (3) by 4 and eq. (4) by 5, we get

   (5)

and    (6)

Subtracting (5) from (6) we get

and now put value of in eq. (3) we get .

So we bought shares of HES and shares of XOM.