help i'm having trouble solving these problems. and this is the equations i'm using.....am i doing this right?

What is the present value today of $30,000 due on after 4 years and discounted at 10% compounded annually?

$

PV= FV x PVfactor

PV=30000x 1/(1+10%)^4

Pv=30000x .6830 (or .683013455)

pv=20,490 or 20,490.40

and it still shows as incorrect....please tell me what i'm doing wrong.

What is the present value today of $40,000 due on after 4 years and discounted at 11% compounded semiannually?

$

pv= FV x 1/1+.055^8

pv=40,000 x .6516

pv= 26,064

What is the present value today of $50,000 due on after 4 years and discounted at 16% compounded quarterly?

$

50,000 x 1/(1+.04)^16

50,000 x .5339

=26,695.40

and it still shows as incorrect....please tell me what i'm doing wrong.

Present Value Issues Using the present value tables, solve the following: (Click here to access the time value of money tables to use with this problem.) Round your answers to two decimal places Required: 1. What is the present value today of $30,000 due on after 4 years and discounted at 10% compounded annually? 20490. 2. What is the present value today of $40,000 due on after 4 years and discounted at 11% compounded semiannually? 26,066 3. What is the present value today of $50,000 due on after 4 years and discounted at 16% compounded quarterly? 26,691