AAMC Chemical and Physical Foundations of Biological Systems (C/P) Full-Length (FL) 2 Practice Test

To find the equivalent resistance of resistors connected in parallel, you can use the formula:

\[

\frac{1}{R_{\text{eq}}} = \frac{1}{R_1} + \frac{1}{R_2}

\]

In this case, the two resistors are 60 Ω and 20 Ω. Substituting the values into the formula gives:

\[

\frac{1}{R_{\text{eq}}} = \frac{1}{60} + \frac{1}{20}

\]

To add these fractions, it can be helpful to find a common denominator. The least common multiple of 60 and 20 is 60. Thus, we rewrite the second fraction:

\[

\frac{1}{20} = \frac{3}{60}

\]

Now we can combine the fractions:

\[

\frac{1}{R_{\text{eq}}} = \frac{1}{60} + \frac{3}{60} = \frac{4}{60}

\]

This simplifies to:

\[

\frac{1}{R_{\text{eq}}} = \frac{1}{15}

\]

To find \(R_{\text