Book Maths Puzzle Logical Reasoning General Mental Ability

An error of 0.02 cm is made while measuring the side of a cube. Find the percentage error in measuring the surface area of the cube, when the side is 10 cm

Read Solution (Total 2)

Error =0.4%
by an error of 0.02cm,Side of cube can be measured as (10-0.02=9.98cm).
Total surface area of cube= 6a^2, where a=side of the cube.
So surface area with the error=6*9.98^2=6*99.60=597.60
If we compare it with original surface area=(597.60/600)100=99.6
So % error=100-99.6= 0.4
12 years agoHelpfull: Yes(1) No(0)

error can be +ve or -ve. the solutn given by devendra is for +ve error.
another way can be like dis
err0r=0.02
side will become=10+0.02
so this will make error={(6*10.02*10.02)-(6*10*10)}/100=0.4004%
12 years agoHelpfull: Yes(1) No(0)

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