NPV included in the IRR calculation? without, correct, nothing, backward, included

slackeranalyst

Let's say I'm given a series of cash flows and given an NPV.

If I'm asked to give the IRR, then the NPV has nothing to do with that right?

series of cash flows
-100
100
50
30

NPV is given as 54.7708.

Through backward induction, I figure out the IRR is 10%.

However, if I just calculate the IRR for the project without the given NPV, the IRR is 47.6323


What's the correct IRR?