### The average price of 10 books is Rs. 12 while the average price of 8 of these books is Rs. 11.75. Of the remaining two books, if the price of one book is 60% more than the price of the other, what is the price of each of these two books?

A. Rs. 5, Rs. 7.50 B. Rs. 8, Rs. 12 C. Rs. 10, Rs. 16 D. Rs. 12, Rs. 14 Answer: Option C

### Solution(By Apex Team)

Total price of the two books = Rs. [(12 × 10) – (11.75 × 8)] = Rs. (120 – 94) = Rs. 26 Let the price of one book be Rs. x Then, the price of other book \begin{aligned}&=\text{ Rs. }(x+60\%\text{ of }x)\\ &=\text{ Rs. }\left(x+\frac{3}{5}x\right)\\ &=\text{ Rs. }\left(\frac{8x}{5}\right)\\ &\text{So},\ x+\frac{8x}{5}=26\\ &\Rightarrow13x=130\\ &\Rightarrow x=10\\ &\text{∴ Price of the other book }\\ &=\text{Rs.}\frac{8\times10}{5}\\ &=\text{Rs.}\ 16\end{aligned}

A. 20
B. 21
C. 28
D. 32

A. 18
B. 20
C. 24
D. 30

A. 10 years
B. 10.5 years
C. 11 years
D. 12 years