Three Cylindrical Shaped Parts Are Joined at Their Ends to Form

Multiple Choice

Three cylindrical shaped parts are joined at their ends to form a mechanical shaft. If the individual parts are $\frac { 1 } { 4 }$ inches, $\frac { 1 } { 8 }$ inches, and $\frac { 9 } { 16 }$ inches long, respectively, what is the total length of the shaft?

A) 1 inch
B) $\frac { 15 } { 8 }$ inches
C) $\frac { 15 } { 64 }$ inches
D) $\frac { 15 } { 16 }$ inches
E) $\frac { 15 } { 32 }$ inches