"Is there a risk free investment?"
You have to break it down this way:
有 没有风险的 投资 吗？ have no-risk investment [QUESTION]?
It seems tricky because 有没有 can also mean "is there a ___" but because there's a 吗 at the end, you know that 有没有 is not signaling a question, but that 没有 should go with 风险 to mean "no risk" or "risk free"
I think the Chinese answer actually says "is there a risk of investment".
It doesn't say "is there a risk free investment". To make it clearly free of risk there has to be a 无 wú in front of the 风险. That says free of risk.
By itself risk free is 没有风险, or doesn't have risk.
有没有 says: does it have a risk or not, just like 有没有 means in every other case it is used. Nothing to do with risk free.
I think, after being here a fair old while, that I've just got this one. The big issue is a) the choice of China not to separate "words" with spaces, and b) Duolingo's choice to separate characters oddly on the tiles. This isn't, 'have/have not a risky investment ?', as one would expect; but, 'have no-risk investment ?'. No wonder Google Translate and many of us come to the exact opposite meaning of Duolingo's.