Find the Indicated Probability by Using the General Addition Rule $\mathrm { A }$

Multiple Choice

Find the indicated probability by using the general addition rule.
-Let $\mathrm { A }$ and $\mathrm { B }$ be events such that $\mathrm { P } ( \mathrm { A } ) = \frac { 1 } { 7 } , \mathrm { P } ( \mathrm { A }$ or $\mathrm { B } ) = \frac { 1 } { 6 }$ , and $\mathrm { P } ( \mathrm { A }$ and $\mathrm { B } ) = \frac { 1 } { 12 }$ . Determine $\mathrm { P } ( \mathrm { B } )$ .

A) $\frac { 5 } { 84 }$
B) $\frac { 3 } { 28 }$
C) $\frac { 1 } { 42 }$
D) $\frac { 11 } { 28 }$