Answer:
NPV of going directly to the market:
Expected value of future cash flows = ($24 x 50%) + ($8.5 x 50%) = $16.25 million
There is a 50/50 chance of being a success or a failure, so to determine the expected value you just multiply each option by 50% and add them.
NPV of test marketing before going directly to the market:
Expected value of future cash inflows = ($24 x 80%) + ($8.5 x 20%) = $20.9 (but delayed by 1 year)
PV of expected cash flows = -1.2 (marketing costs) + $20.9/1.11 = $17.80 million