At the opening of a trading day at a certain stock exchange, the price per share of stock K was $10. If the price per share of stock K was $15 at the closing of the day, what was the percent increase in the price per share of stock K for that day?  Pick one.
A) 1.4% B) 50% C) 11.1% D) 12.5% E) 23.6%
Opening = 10   Closing = 15   Rise in price = 5   So, percent increase = 5/10 * 100= 
<gadget id="calculator">5/10 * 100</gadget>
<output>50</output>
50%   Answer : 50%
<result>B</result>
At the opening of a trading day at a certain stock exchange, the price per share of stock K was $10. If the price per share of stock K was $15 at the closing of the day, what was the percent increase in the price per share of stock K for that day?