Question

The formula for percentage increase I (given as a decimal) of an investment is I=S−PP I = S − P P , where P P is the purchase price and S S is the sale price. You sell a stock at a price of $91, earning a percentage increase of 30%. What was the purchase price of the stock?

Answer 1

$130

Explanation:

Given:

I = (S − P) / P

where,

P = purchase price and

S = sale price.

What was the purchase price of the stock?

I = 30%

S = $91

I = (S − P)/P

30% = (91 - P) / P

0.3 = (91 - P) / P

Cross product

0.3P = 91 - P

0.3P + P = 91

0.7P = 91

P = 91 / 0.7

P = $130