Final answer:
The original number of persons was found to be 65 by setting up an equation and solving a quadratic equation, taking into account that each person would get Rs.30 less if there were 15 more people.
Step-by-step explanation:
To find the original number of persons, we can set up an equation based on the information given. Let x be the original number of persons. Then each person would get Rs.6500/x when the money is divided equally. If there were 15 more persons, the number of persons would become x + 15, and each person would receive Rs.6500/(x + 15). We are told that in this case, each person would get Rs.30 less, so:
Rs.6500/x - Rs.30 = Rs.6500/(x + 15)
Now, we can solve for x:
- Multiply both sides by x(x + 15) to eliminate the fractions: x(x + 15)(6500/x) - x(x + 15) * 30 = x(x + 15)(6500/(x + 15))
- Simplify the equation: 6500(x + 15) - 30x(x + 15) = 6500x
- Distribute and combine like terms: 6500x + 97500 - 30x^2 - 450x = 6500x
- Subtract 6500x from both sides and simplify: -30x^2 - 450x + 97500 = 0
- Divide by -30 to simplify the equation: x^2 + 15x - 3250 = 0
- Factor the quadratic equation: (x + 50)(x - 65) = 0
- Since the number of people cannot be negative, we take x = 65 as the solution.
Therefore, the original number of persons is 65.