Answer:
a. Payback period:
Board game:
= Year before payback + Amount left / Cashflow in year of payback
= 1 + (1,200 - 690) / 950
= 1.54 years
Game DVD:
= 1 + (2,700 - 1,750) / 1,570
= 1.61 years
b. NPV
Board Game
= 690 / 1.12 + 950 / 1.12² + 210 / 1.12³ - 1,200
= $322.88
Game DVD
= 1,750 / 1.12 + 1,570 / 1.12² + 800 / 1.12³ - 2,700
= $683.52
c. IRR
Look at attached picture
Board Game IRR = 29%
Game DVD IRR = 28%
d. Incremental IRR
Look at attached picture
= 27%