An investment calculation problem about corporate finance?

If the discount rate is 5%, X: NPV = 6000 * (P/A, 5%, 9).

Y:NPV=8000*(P/A，5%，6)

If the discount rate is 15%, X: NPV = 6000 * (P/A, 15%, 9).

Y:NPV=8000*(P/A， 15%，6)