Use the Formula $R _ { t } = \frac { R _ { 1 } R _ { 2 } } { R _ { 1 } + R _ { 2 } }$

Multiple Choice

Use the formula $R _ { t } = \frac { R _ { 1 } R _ { 2 } } { R _ { 1 } + R _ { 2 } }$ to find the total resistance $\left( R _ { t } \right)$ if one resistance $\left( R _ { 1 } \right)$ is 15 ohms and the second resistance $\left( R _ { 2 } \right)$ is 10 ohms.

A) 0.17 ohms
B) 5 ohms
C) 6 ohms
D) 1 ohms