Bunuel
In 2010, a library contained a total of 11500 books in two categories - fiction and nonfiction. In 2015, the library contained a total of 12760 books in these two categories. During this period, there was 10% increase in the fiction category while there was 12% increase in the non-fiction category. How many fiction books were in the library in 2015?
A. 5500
B. 6000
C. 6160
D. 6500
E. 6600
Are You Up For the Challenge: 700 Level QuestionsSolution:
Let f and n be the number of fiction and nonfiction book in library in 2010, respectively
In 2015,
• Number of fiction books = \(f+\frac{10}{100}*f = \frac{110}{100}*f\)
• Number of nonfiction book = \(n + \frac{12}{100}*n = \frac{112}{100}*n\)
o Total books = \(\frac{110}{100}*f + \frac{112}{100}*n = 12760\)
o \(110*f + 112*n = 12760*100\)…(ii)
Equation (i) can be rewritten as:
• n = 11500 – f
• On substituting this value in equation (ii), we get
• 110*f + 112(11500-f) = 12760*100
• 110*f – 112*f +115*112*100 = 12760*100
o 2*f = (12880-12760)*100
o \(f = \frac{120*100}{2} = 6000\)
Number of fiction books in 2015 = 6000*1.1 = 6600
Hence, the correct answer is
Option E.