If R Is the Total Resistance of Three Resistors, Connected $R _ { 1 } , R _ { 2 } , R _ { 3 }$

Multiple Choice

If R is the total resistance of three resistors, connected in parallel, with resistances $R _ { 1 } , R _ { 2 } , R _ { 3 }$ , then $\frac { 1 } { R } = \frac { 1 } { R _ { 1 } } + \frac { 1 } { R _ { 2 } } + \frac { 1 } { R _ { 3 } }$ . If the resistances are measured in ohms as $R _ { 1 } = 30 \Omega , R _ { 2 } = 35 \Omega \text { and } R _ { 3 } = 50 \Omega$ , with a possible error of 0.8% in each case, estimate the maximum error in the calculated value of R.

A) 0.347 $\Omega$
B) 0.476 $\Omega$
C) 0.291 $\Omega$
D) 0.098 $\Omega$
E) 0.957 $\Omega$