Bunuel wrote:

By the start of the lunch break of a conference, 3/8 of the original participants had already left. By the end of the conference, 1/3 of the original participants remained. Approximately what percentage of the original participants left between lunch and the end of the conference?

A. 25%

B. 29%

C. 37%

D. 63%

E. 67%

Assign values and calculateUse LCM of denominators

Let original participants be \(x = 24\)

\(\frac{3}{8}\) leave before lunch:

\(\frac{3}{8} * 24 = 9\) left before lunch

\((24 - 9) = 15\) remain until the lunch break

At the end, \(\frac{1}{3}\) of original \(24\) remain

\(\frac{1}{3} * 24 = 8\) remain until the end

How

many left the conference between lunch and the end of the conference?

At the lunch break: 15 people were there

At the end: 8 people were there

\((15 - 8) = 7\) left the conference between lunch and the end of the conference

Approximately what percentage of original participants left between lunch and the end of the conference?

\(\frac{7}{24} = .29xxx \approx {29}\) percent

Answer B

Assign values and estimate/eliminateFrom the numbers above, 7 of 24 remain.

\(\frac{7}{24}\) = what percent?

Compare: \(\frac{8}{24} = 33.33\) percent

\(\frac{7}{24}\) is a lower percentage than \(\frac{8}{24}\)= 33.33%

Answers C, D, and E are out.

Answer A, 25 percent, would be exactly \(\frac{6}{24}\)

\(\frac{7}{24}\) is a higher percentage than \(\frac{6}{24}\)

Answer A, too low, is out. By POE:

Answer B) 29 %

_________________

In the depths of winter, I finally learned

that within me there lay an invincible summer.

-- Albert Camus, "Return to Tipasa"