Consider investment opportunity that will generate a cash flow of $250,000 per year every year in perpetuity. The first cash-flow of $250,000 is one year from now (time = 1). How much are you willing to invest at (time = 0) if you want to have an IRR of 20%?
Would this yield the same result as a non perpetual IRR question? Thats word is throwing me off.
For a 20% IRR you would pay $1,250,000 for that stream of cash flows.
For a non-perpetual annuity, the question would have to specify the number of years of income. Since it’s a perpetuity, the answer is indeed 250,000/0.2 = $1,250,000, as Chad pointed out. 
ETA: If you have a BAII+, go into the CF worksheet, enter Cf0=0, C01=250000, F01 =1000. In the NPV worksheet, use I=20 and CPT NPV. Prepare to be amazed!!!