Question

There is an N-box train.Find the value of j such that the following statement is true: "the i-th box from the front of the train is the j-th box from the back."

1 <= i <= N

Answer 1

Answer:

j = N + 1 — i

explanation:

so, number of box behind the i-th box = j —1

number of box in front of the i-th box = i—1

N = (i—1) + ( j—1) + 1

or, N = I + j — 1

so, j = N + 1 — I