Question 1195052

A boy bought 200 books .he sold 80 of books at a profit 15% and the remaining ones at a profit of 50% he realized rs.27200 in total .what was his cost of books?
<pre>Let cost of the 200 books be C
Then cost of each book = {{{C/200}}}
With 80 books being sold at a 15% profit, we get the selling price of those 80 books as: {{{matrix(1,7, 1.15(80C/200), "=", 1.15(2C/5), "=", .23(2C), "=", .46C)}}}

With 120 (200 - 80) books being sold at a 50% profit, we get the selling price of those 120 books as: {{{matrix(1,7, 1.5(120C/200), "=", 1.5(3C/5), "=", .3(3C), "=", .9C)}}}
As the total profit was RS 27,200, we get: .46C + .9C = 27,200
                                                1.36C = 27,200
                         Cost of the 200 books, or {{{highlight_green(matrix(1,5, C, "=", "27,200"/1.36, "=", highlight(matrix(1,2, RS, "20,000"))))}}}
You can do the check!!</pre>