In measuring the sides of a rectangle, one side is taken 20% in excess and the other 10% in deficit. Find the error per cent in area calculated from the measurement?  Pick
A) 12% deficit
B) 10% excess
C) 8% excess
D) 9% excess
E) none of these
Since Side1 x Side2 = Area   Therefore, error% in area   = ( x + y + xy/100) %   = [20 - 10 + ( -10 x 20)/100]% or 8%   i.e., 8% excess   ANSWER:8% excess
<result>C</result>
In measuring the sides of a rectangle, one side is taken 20% in excess and the other 10% in deficit. Find the error per cent in area calculated from the measurement?