A clerical worker takes 2 times as long to finish a job as it does an executive secretary.

A clerical worker takes 2 times as long to finish a job as it does an executive secretary. Working together, it takes them 5 hours to finish the job. How long would it take the clerical worker, working alone, to finish the job?

---

1/5 = rate together {job/hour}
1/x = executive rate {job/hour}
1/(2x) = clerical rate {job/hour}

​1/x + 1/(2x) = 1/5 {executive rate + clerical rate = together rate}
10 + 5 = 2x {multiplied entire equation by 10x to eliminate fractions}
15 = 2x {combined like terms}
x = 7.5 {divided each side by 2}
2x = 15 {substituted 7.5, in for x, into 2x}

It would take the clerical worker 15 hours, working alone.

Ask the House
​