21. One gram of salt is dissolved in water that is filled to a height of 5 cm in a beaker of diameter 10 cm. The accuracy of length measurement is 0-01 cm while that of mass measurement is 0-01 mg. When measuring the concentration C, the fractional error AC/C is (A) 0-8% (C) 0-5% (B) 0-14% (D) 0-28%
dear you are doing right, but these is a some calculation mistake in your ans otherwise your approach is right.... do calculation carefully...option d is correct.. best regards