1. risk/reward comparison

Ok I feel this is probably really easy but I just can't get it.

I have 100 units and I'm trying to figure out which way to risk said units to the largest final result.

I have two ways of risking them that reward me at different scales.

First is that I'm working off of the premise that I will have a positive result on every event %60 of the time.

Now the first, and simple, way I can do this is to risk 20 units on a single event for a payoff of 1.9:1 units. Since I expect to win 60% of the time, I win 3 of the 5 risks and receive 38 units back from each risk. So therefore at the expected positive result I will on average finish with 114 units.

The second, and this is where I'm stuck, is to risk 20 units on two events jointly to receive a payoff of 3.6:1 units. To trigger that payoff I'd have to have both connected events be positive. So basically I'd have 5 separate risks with 2 events in each. The payoff is obviously more but is it worth the added risk?

I'm trying to determine which course of action would on average result in a higher end amount of units. Extend this out to 10000 units for example still at 20 per risk.

Sorry if I'm missing a simple answer or if this doesn't make sense. Thanks in advance.