Let the amount with each of the friends be denoted by the first letter of their names. Now A > 2H. So H must be 300. And A is either 700 or 900. And S < H + M. So S can be either 500 or 700. The following three cases are possible:
Rs. 300
Rs. 500
Rs. 700
Rs. 900
Case 1
H
S
M
A
Case 2
H
S
A
M
Case 3
H
M
S
A
Now if we analyse the table we can see that the absolute difference in the amounts with Saral and Himanshu is equal to the absolute difference in the amounts with Abhishek and Mubashir in all the three cases.