Question

there are 1770 more letters in post box A than in post box B.485 letters are transferred form post box A to post box B.How many letters are there un post box A than in post box B at the end

Answer 1

difference will reduce to = 1770-485×2= 1770-970= 800.
so there are 800 more letters in A in comparison of B.

Answer 2

Letter in post box A is x+1770
Letter in post box B is x

A/Q
X + 1770 - 485 = X + 485
X + 1285 = X + 485

letters in post box A than in post box B at the end, X + 1285 - (X + 485)
X + 1285 - X - 485 = 800