Seating Arrangement Order and Position

Let us determine positions from left and right:

1. Ram is 18th from right.
2. Sunil is 16th to the left of Ram, so there are 15 people between Sunil and Ram.
3. Jack is 4th to the right of Sunil $\Rightarrow$ Sunil is 4th to the left of Jack.
4. Jack is 11th from left, so Sunil's position from left $= 11 - 4 = 7$th from left.
5. Since Sunil is 7th from left, there are 6 people to his left.
6. Total people $= 6 \text{ (left of Sunil)} + 1 \text{ (Sunil)} + 15 \text{ (between Sunil and Ram)} + 1 \text{ (Ram)} + 17 \text{ (right of Ram)} = 40$.