Robert's salary was increased by 50% and subsequently decreased by 10%. how much percentage does he gain?  Choose one
A) 15%
B) 20%
C) 10%
D) 25%
E) 30%
let original salary be $100   increased salary = 10% of (150% of $100) = (10/100)*(150/100)*100= 
<gadget id="calculator">(10/100)*(150/100)*100</gadget>
<output>15</output>
$15   increase= 15%   correct option is 15%
<result>A</result>
Robert's salary was increased by 50% and subsequently decreased by 10%. how much percentage does he gain?