ruth can assemble a computer by herself in 55 minutes. erin does the same job in 60 minutes. how long will…

ruth can assemble a computer by herself in 55 minutes. erin does the same job in 60 minutes. how long will it take them to assemble a computer working together? write your answer as a fraction in lowest terms.
Answer
Explanation:
Step1: Identify individual work rates
Ruth's rate is $\frac{1}{55}$ computers/minute; Erin's rate is $\frac{1}{60}$ computers/minute.
Step2: Determine the combined work rate
$$\text{Combined Rate} = \frac{1}{55} + \frac{1}{60}$$
Step3: Find a common denominator
$$\frac{12}{660} + \frac{11}{660} = \frac{23}{660}$$
Step4: Calculate time by taking the reciprocal
$$\text{Time} = \frac{1}{\text{Combined Rate}} = \frac{660}{23}$$
Answer:
$\frac{660}{23}$ minutes