give information abt share agreement bwn land owner and builder?

i am planning to buy flat in bangalore. when i verified all documents, i came to know that the agreement which has share (50% and 50%) bwn land owner and builder has been registered. But the agreement which has exact share(which flat belongs to whom ) is not registered. is this agreement also need to be registered?

A calculus problem on continuous annuity with withdrawal.?

Show that a continuous annuity with withdrawal rate N = $5000/yr and interest rate r = 8%, funded by an initial deposit of Po= $75,000, never runs out of money.

As I understand the differential equation for this type of problem is
dP/dt = r (P-N/r)
For r, I should substitute 8/100 = 0.08. Is this correct?
This is how I solved the equation:
dP/(P – N/r) = r dt
ln(P – N/r) = rt + ln(C), where C is a constant
ln(P – N/r) – ln(C) = rt
ln[(P – N/r)/C] = rt
P – N/r = C e^rt
P = N/r + C e^rt
Substituting the given value of P at t = 0, we can find the value of C. I got C = $12500
P = N/r + 12500 e^rt
P = 5000/.08 + 12500 e^rt
P = 62500 + 12500 e^(.08t)
From the above equation, P > 0 for all values of t. Therefore the annuity never runs out of money.
Is my analysis correct?
What surprises me is the equation P = N/r + C e^rt
Since N is the withdrawal rate, should we not get an equation which shows that P decreases when N increases? But the equation P = N/r + C e^rt shows just the opposite.

What type of taxes are applicable on software developing and selling.?

We are small s/w developement firm based in jaipur rajasthan.
engaged in web and desktop application development services.
Now we are going to develop a public utility software and planinng to sell it in public and gov sector within the sate and out of state customers.
Can any one let us is their any requirement to register our firm. and what type of taxes are aplicable at what rate?
Thanks in adv.