Private Equity: Calculation of Carried Interest only, interest, however, carried, example

AndyNZ

Example 2 on Reading 49, page 66:

The example is pretty easy to follow, however towards the bottom they say the IRR on the project is only 6.1% and doesn't clear the hurdle rate of 8%, thus no carried interest may be paid to the GP. How did they calculate the IRR as 6.1% ?

Matt