Let's assume, person starts with Rs x

After 1st temple visit, he is left with Rs (2x-100)

After 2nd temple visit, he is left with Rs (4x-300)

After 3rd temple visit, he is left with Rs (8x-700)

After 4th temple visit, he is left with Rs (16x-1500), which is zero (as he is left with empty pockets)

Hence he started of with x i.e. Rs 1500/16 i.e. Rs 93.75

Answer: Rs 93.75