In measuring the length and breadth of a rectangle, errors of 5% and 3% in excess, respectively, are made. The error percent in the calculated area is
8.15%
Let actual length and breadth of the rectangle be 'l' and 'b' respectively.
The measured sides are (l+0.05l) and (b+0.03b) i.e. 1.05l and 1.03b
∴ Measured area =(1.05l)(1.03b)
Actual area =lb
Error in area=1.0815lb−lb =0.0815lb
∴% error=Error in areaActual area×100
⇒% error=0.0815lblb×100%=8.15%