emmak wrote:
Attendance at a library for Saturday and Sunday combined was 50% of the average attendance for the preceding 5 days. The weekend's attendance was approximately what percentage of the attendance for the entire 7-day period?
A. 9%
B. 11%
C. 15%
D. 30%
E. 33%
Let the days of week be numbered as xn
So, x6+x7 =50% of (x1+......+x5)/5 = (x1+......+x5)/10
-> (x1+......+x5) = 10*(x6+x7)
So, (x1+x2+.....+x6+x7) = 10*(x6+x7) + (x6+x7) = 11*(x6+x7)
So percentage =(x6+x7)/[11*(x6+x7)] *100 = 9.09
Answer
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