Question

A person has ​$28,000 invested in stock A and stock B. Stock A currently sells for ​$50 a share and stock B sells for ​$60 a share. If stock B triples in value and stock A goes up​ 50%, his stock will be worth ​$69,000. How many shares of each stock does he​ own?

Answer 1

Number of stock A = 200

Number of stock B = 300

Explanation:

Let :

Number of stock A shares = a

Number of stock B shares = b

Worth of stock A = 50 * a = 50a

Worth of stock B = 60 * b = 60b

50a + 60b = 28000 - - - (1)

Triple the value of stock B:

3 * 60 = 180

Value of stock A goes up by 50%

(100 + 50)% * 50 = 1.5 * 50 = 75

75a + 180b = 69000 - - - (2)

50a + 60b = 28000

75a + 180b = 69000

Multiply equation 1 by 3 and subtract

150a + 180b = 84000

75a + 180b = 69000

75a = 15000

a = 15000/75

a = 200

75(200) + 180b = 69000

15000 + 180b = 69000

180b = 69000 - 15000

180b = 54000

b = 300