By increasing the list price of a book by Rs. 10 a person can buy 10 l

1.	By increasing the list price of a book by Rs. 10 a person can buy 10 less books forRs. 1,200. Find the original list price of the book
Answer» Let original book price=X Number of books that can be bought in 1200 =1200/x Suppose price increases by 10. New price=x+10 No of books that can be bought in new price= 1200/(x+10) Now, this number is 10 less than the no of books that can be bought in 1200 at ‘x’ price. So, 1200/x= 1200/(x+10) + 10 Simplifying the above we get X^2 +30x -1200=0 x=-b+-√b^2-4acx=30+-√900+4800/2x=30 and -40ignoring -40 as number should be positive. So original book price is Rs 30

By increasing the list price of a book by Rs. 10 a person can buy 10 less books forRs. 1,200. Find the original list price of the book

Answer»

Let original book price=X

Number of books that can be bought in 1200 =1200/x

Suppose price increases by 10. New price=x+10

No of books that can be bought in new price= 1200/(x+10)

Now, this number is 10 less than the no of books that can be bought in 1200 at ‘x’ price.

So, 1200/x= 1200/(x+10) + 10

Simplifying the above we get

X^2 +30x -1200=0

x=-b+-√b^2-4acx=30+-√900+4800/2x=30 and -40ignoring -40 as number should be positive.

So original book price is Rs 30