A B C and D share a loot A gets a of the total B gets b of the remaining after A has taken his share...........

Explanation:

Let total amount = T
A would have got T * a. After A takes his share, there would be T (1 - a) left
B would have got T (1 - a) * b
C would have got T (1 - a)(1 - b) * c
D would have got T (1 - a) (1 - b) (1 - c)
D gets a % less than what A gets, or, T *a (1 - a) = T(1 - a) (1 - b) (1 - c), or
a = (1 - b)(1 - c) ------(1)
B and C get the same amounts, or (1 - a) * b = (1 - a) * (1 - b) * c, or b = (1 - b) c, or, b = c - cb, or
b = c/c + 1 ......(i)
b = 2a -------(3)
Substituting, Equations (2) in and (3) in (1), we get

A gets 20% of the loot, B gets 40% of the remaining 80%, or 32% of the loot.
C gets 66.6% of 48%, or 32% of the overall loot.
And D gets the final 16% of the overall amount (20% lesser than A's share).
A got 20% of overall, C got 32% of overall. Or, C got 160% of A
A would have got Rs. 200, D Rs. 160. A would have got Rs. 40 more than D.
Hence, the answer is 160% , A got Rs.40 more than D