Let's break down the problem step by step to find out how many books Anirudh bought and the price of each book.
Setting Up the Problem
Let the number of books Anirudh bought be x and the price of each book be p. According to the information given:
- The total cost of the books is Rs. 60, so we can write the equation: xp = 60.
- If he had bought 5 more books, the number of books would be x + 5, and the price per book would be p - 1.
- The total cost remains the same, leading to the equation: (x + 5)(p - 1) = 60.
Formulating the Equations
From the first equation, we can express p in terms of x:
p = 60/x
Now, substitute this value of p into the second equation:
(x + 5)(60/x - 1) = 60
Solving the Equation
Expanding the equation:
(x + 5)(60/x - 1) = 60
60 + 300/x - x - 5 = 60
Now, simplifying gives:
300/x - x - 5 = 0
Multiplying through by x to eliminate the fraction:
300 - x^2 - 5x = 0
Rearranging the Quadratic Equation
This can be rearranged to:
x^2 + 5x - 300 = 0
Finding the Roots
Now, we can use the quadratic formula:
x = (-b ± √(b² - 4ac)) / 2a
Here, a = 1, b = 5, and c = -300.
Calculating the discriminant:
b² - 4ac = 5² - 4(1)(-300) = 25 + 1200 = 1225
Now, substituting into the formula:
x = (-5 ± √1225) / 2
x = (-5 ± 35) / 2
Calculating the Values
This gives us two potential solutions:
- x = 15 (valid since it must be positive)
- x = -20 (not valid)
Determining the Price
Now that we know x = 15, we can find the price per book:
p = 60/x = 60/15 = 4
Final Results
Anirudh bought 15 books, and each book cost Rs. 4.