42nd B.P.S.C. (Pre) 1997-98
A person buys 11 books for Rs. 10 and sells 10 books for Rs. 11. What percent profit will he make?
a12%
b12.5%
c21.5%
d21%✓ Correct
Explanation
Cost price of 1 book = $$\frac{10}{11}$$ Rs. Selling price of 1 book = $$\frac{11}{10}$$ Rs.
general-mental-ability