Question

Lisa Myers has ​$47,000 invested in stock A and stock B. Stock A currently sells for ​$20 a share and stock B sells for ​$90 a share. If stock B doubles in value and stock A goes up​ 50%, her stock will be worth ​$93,000. How many shares of each stock does she ​own?

Answer 1

suppose no of shares of stock A : X and no of shares of stock B : Y

so, 20(A) + 90(B) = 47000

value of A can be written as A = [47000 - 90(B)]/20 (eq 1 )

now stock A value is 50% up = $30 (20+ 50% up)

and stock B value is doubled = $180 ( double from $90)

so equation will be 30(A) + 180(B) = 93000

we will put value of A (from eq 1) in above equation

30[47000 - 90(B)]/20 + 180 (B) = 93000

(30/20)[47000 - 90(B)] + 180(B) = 93000

(1.5)[47000 - 90(B)] + 180(B) = 93000

70500 - 135(B) + 180 (B) = 93000

45(B) = 93000 -70500 = 22500

B = 500 shares

shares of A = [47000 - 90(500)]/20 = [47000-45000]/20 = 100

answer : shares of A = 100, shares of B = 500 (THUMBS UP PLEASE)