Explanation:

Let the amount of money with X, Y and Z be x, y and z.
As per the question,
If Y gives me Rs. 40, then Y will have half of as much as Z.
That is, y – 40 = z/2
Or z = 2y - 80 ……(i)
If Z gives me Rs. 40, then three of us will have equal amount.
That is, x + 40 = y = z – 40
So, x = y – 40
And z = y + 40 ……(ii)
Using statements (i) and (ii), we get:
2y – 80 = y + 40
Or y = 120
So, x = y – 40 = 120 – 40 = 80
And z = y + 40 = 120 + 40 = 160
So, money with X, Y and Z will be Rs. 80, Rs. 120, and Rs. 160.
Total amount of money with X, Y and Z = x + y + z = 80 + 120 + 160 = Rs. 360