Bunuel wrote:

Painting at a constant rate, Lauren completes 3/5 of a job in 6 hours. How many hours will it take her to complete the job if she continues at the same rate?

A. 6/5

B. 2

C. 12/5

D. 3

E. 4

ProportionIf it takes 6 hours to finish 3/5 of work, it will take

T (?) hours to finish 2/5 of work remaining

Set up a proportion:

\(\frac{(\frac{3}{5})}{6}=\frac{(\frac{2}{5})}{T}\)

\(\frac{12}{5}=\frac{3}{5}T\)

\(T = 4\) hours remain

Answer E

Work formula- harder, but... \(\frac{2}{5}job,

j\) remains

Using (R*T = W), find "effective" work rate.

Rate is not \(\frac{3}{5}\). WORK = \(\frac{3}{5}j\)

Effective (real) work rate:

\(R=\frac{W}{T}\)

\(Rate=\frac{\frac{3}{5}j}{6hrs}=\frac{3j}{30hrs}=\frac{1j}{10hrs}\)

\(T=\frac{W}{R}=\frac{\frac{2}{5}}{\frac{1}{10}}=(\frac{2}{5}*\frac{10}{1})=4\) hours

Answer E

_________________

In the depths of winter, I finally learned

that within me there lay an invincible summer.

-- Albert Camus, "Return to Tipasa"