A variable w is related to three other variables x, y and z as w = xy/z. The variables are measured with meters of accuracy ± 0.5% reading, ± 1% of full scale value and ± 1.5% reading. The actual readings of the three meters are 80, 20 and 50 with 100 being the full scale value for all three. The maximum uncertainty in the measurement of w will be

• A.  ± 8%
• B.  ± 7%
• C.  ± 5%
• D.  ± 6%

Answer: (B)