Let the sum of the first n terms of a non-constant A.P., a1, a2, a3, ..... be $50n + {{n(n - 7)} \over 2}A$, where A is a constant. If d is the common difference of this A.P., then the ordered pair (d, a50) is equal to

Question

Let the sum of the first n terms of a non-constant A.P., a₁, a₂, a₃, ..... be $50n + {{n(n - 7)} \over 2}A$, where A is a constant. If d is the common difference of this A.P., then the ordered pair (d, a₅₀) is equal to

(A, 50+45A)