Rs. 13000 was divided equally among a certain number of persons. Had there been 15 more persons, each would have got Rs. 60 less. Find the initial number of persons.

The initial number of persons is 50.

Each share = 13000/n; with 15 more, share = 13000/(n + 15).

13000/n - 13000/(n + 15) = 60.

13000 x 15 = 60 x n(n + 15), so n(n + 15) = 3250.

n^2 + 15n - 3250 = 0 factors to (n - 50)(n + 65) = 0.

n = 50.