Solve the Problem $R$ Produced by Wiring Resistors Of $R _ { 1 }$

Multiple Choice

Solve the problem.
-The resistance $R$ produced by wiring resistors of $R _ { 1 }$ and $R _ { 2 }$ ohms in parallel can be calculated from the formul $\frac { 1 } { R } = \frac { 1 } { R _ { 1 } } + \frac { 1 } { R _ { 2 } } .$
If $R _ { 1 }$ and $R _ { 2 }$ are measured to be 10 ohms and 6 ohms respectively and if these measurements are accurate to within $0.05$ ohms, estimate the maximum possible error in computing R.

A) 0.032
B) 0.016
C) 0.021
D) 0.027