An investor owns shares of Stock A and Stock B. The investor owns a total of 200 shares with a total value of $4000. How many shares of each stock does the investor own?

Answer 1

A+B=200

A=200-B

PaA +PbB = 4000

pa(200-B) + PbB = 4000

200Pa -PaB + PbB = 4000

(Pa+Pb)B = 4000-200Pa

B = (4000-200Pa)/(Pa+Pb)

A = 200-B = 200- (4000-200Pa)/(Pa+Pb)

Plug in Pa and Pb to solve for the number of shares of A and B. Pa=price of A's stock. Pb= B's price