mr.james need to have Rs.75000 at the end of 5 years.How much he have to save each year if rate of interest is 8% p.a compounded semiannualy?

The answer depends upon when in the year, and in what amount, the deposits are made.

Assume the savings are deposited at the beginning of years 1,2,3, 4, and 5, in equal amounts. Call that annual amount X. In each year, the already-deposited savings increase by a factor
(1.04)^2 = 1.0816
The funds that are left for a full five years get multiplied by 1.0816^5 = 1.480244.
The funds that are deposited at the beginning of the second year and are left 4 years get multiplied by a factor 1.0816^4 = 1.368569
The funds that are left 3 years get multipled by a factor 1.265319
The funds that are left 2 years get multiplied by a factor 1.169859.

Now solve this equation:
X(1.480244 +1.368569 +1.265319 +1.169859 + 1.081600) = Rs.75000 = 6.365591 X
X= 11,782.10 Rupees per year