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
a)Rs.15
b)Rs.20
c)Rs.25
d)Rs.30

• by the options
  take 20rs then books come in 300= 300/20= 15
  now rate decease by 5rs then cost is 15, so book come in 300= 300/15=> 20
  its satisfy the condition 5 extra book we can buy.
  
• 12 years agoHelpfull: Yes(17) No(7)
• ans b)20
  300/(x-5)-300/x=5
  x=20
• 12 years agoHelpfull: Yes(12) No(0)
• b)Rs.20
  Let list price be rs.x
  so, 5+(300/x)=300/(x-5)
  (5x+300)/x=300/(x-5)
  (5x+300)*(x-5)=300x
  5x^2+275x-1500=300x
  5x^2-25x-1500=0
  x^2-5x-300=0
  x^2-20x+15x-300=0
  (x-20)(x+15)=0
  x=20 & -15
  but -15 is not possible so x=20 ans.
• 12 years agoHelpfull: Yes(4) No(2)
• the answer is rs 20.
• 12 years agoHelpfull: Yes(3) No(7)
• 20/- is answer
  total no of books bought will be 15
  so cost will be 15*15=225
  again 5 more books can be bought
  price for 1 book is 15
  so 15*5=75
  225+75=300/-
• 10 years agoHelpfull: Yes(2) No(0)
• let orgnal price 20, 300/20=15books, price reduced 15*5=75..
• 12 years agoHelpfull: Yes(0) No(12)
• Let 'x' be the no of book that we buy with 5 rupee less from the original book price and we buy 5 more books with the rest money each costing original book price.
  
  so the no of cases arises are
  
  Case 1:
  x(15-5)+5(15)=300
  Solving this equation we get the value of x =22.5 (which is a fraction value)
  so this case is not possible.
  
  Case 2:
  x(20-5)+5(20)=300
  Solving this equation we get the value of x =13.33 (which is a fraction value)
  so this case is not possible.
  
  Case 3:
  x(25-5)+5(25)=300
  Solving this equation we get the value of x =8.75 (which is a fraction value)
  so this case is not possible.
  
  Case 4:
  x(30-5)+5(30)=300
  Here we get the value of x =6 (which can be possibly a no. of book, so the original price of the book is 30).
  
  Answer Question
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• 11 years agoHelpfull: Yes(0) No(3)
• 15...
  let the number of books initially to be bought be n and the cost price be x.
  n*x=300.
  after reduction,,
  (x-5)(n+5)=300.
  on solving,
  x=15
  
• 11 years agoHelpfull: Yes(0) No(0)
• ithink its answar is 25
• 11 years agoHelpfull: Yes(0) No(2)
• answer is b)Rs.20
  
• 11 years agoHelpfull: Yes(0) No(0)
• 20 will be its initial price
• 10 years agoHelpfull: Yes(0) No(0)
• b is correct ans
  
• 10 years agoHelpfull: Yes(0) No(0)
• book no=n && price/book=x
  300/n=x.....(I)
  300/(n-5)=x+5...(II)
  solve I && II
  n=20/-15
  Ans. is 20
• 10 years agoHelpfull: Yes(0) No(0)
• no.of books be x
  x+5------300/-
  x(x+5)=300
  or lets check with 20/-
  then no.of books will be 300/20=15
  if we reduce the price by 5 and increase the no.of books by 5 then we must get 300/- cost total..
  15/- * 20 books =300/-
  so,original cost might be 20/-....
  
• 10 years agoHelpfull: Yes(0) No(0)
• Let the no. of books be - n
  Let original cost be - x
  For cost price of x, person buy n books for 300 rupees.
  300/n=x -1
  If cost price reduced by 5, (x- 5 )
  Person buy (n+5) books for 300 rupees
  300/n+5=(x-5) -2
  Solve equation 1&2
  Gives value of number of books, n=15
  Put this value of n in 1 equation
  Gives the original cost x = 20.
• 9 years agoHelpfull: Yes(0) No(1)