If the list price of a book is reduced by Rs. 5, then a person can buy 5 more books for Rs. 300. The original cost of the book is
(1) Rs. 15
(2) Rs. 20
(3) Rs. 25
(4) Rs. 30

• (2) Rs. 20
  
  If x is earlier price, then
  
  300/(x-5)- 300/x = 5
  solving this , we get, x=20 or -15 out of which only 20 is acceptable.
• 13 years agoHelpfull: Yes(15) No(3)
• Let the no. of books, a person can buy = n
  
  Price of each book = x
  
  The Person has 300 Rs hence,
  
  nx=300 ...(1)
  
  If price of each book is reduced by Rs. 5 he can buy 5 more books in 300 Rs.
  
  (n+5)(x-5)=300
  
  nx-5n+5x-25=300 ...(2)
  
  from eq. 1 nx=300 and n=300/x
  
  so eq. 2 reduces to
  
  x^2-5x-300=0
  
  so x=20 or -15
  
  hence initial price of each book = 20 Rs.
• 9 years agoHelpfull: Yes(3) No(1)
• Let no of books x and price =y then xy=300, (x+5)(y-5)=300 thus y-x=5 so we get 20 and 20
• 9 years agoHelpfull: Yes(2) No(1)
• Let x books bought for Rs.300. Let cost per book is Rs. y.
  Then x*y=Rs.300 --(1)
  by the condition another equation can be formed as ( x+5)*(y-5)=300 --(2)
  =>xy+5y-5x-25=300
  =>300+5y-5x-25=300
  => 5y-5x=25
  => y-x=5
  Now substitute y value from (1)
  => 300/x-x=5
  x2+5x-300=0 --(3)
  Solving (3) we get x=15,y=20
  Thus as mentioned initial cost of the book is Rs20
• 4 years agoHelpfull: Yes(0) No(0)