Regular annual pension
Firstly, the formula you have used for FV is equivalent to that shown here. What it calculates, with your numbers, is the value after 7 years of investing 200,000 annually at a compound rate of 7% (as a rough confirmation, 1,851,960 is somewhat more than 7 x 200,000).  Instead, you need the value after 7 years (or 6 years if the man is already at the end of his 24th year) of a one-off investment of 200,000 (call that V).

Secondly, the simple division by 20 takes no account of the interest earned during years 31-50. To allow for this, you need the present value of an annuity formula (source):

$$P\Bigg[\frac{1-(1+i)^{-n}}{i}\Bigg]$$

Set this formula equal to V and treat the annual (periodic) payment P as an unknown to be found.