[jay_shark]

If you have monotone cards in spades without loss of generality , then the probability the flop comes monotone in spades is :

11C3/50c3=0.008418

monotone in any of the three other suits :
13C3/50c3= 0.0145

Therefore , the probability the flop comes monotone in any of the suits when you hold two suited cards is :

3*13c3/50c3 + 11c3/50c3 = 0.0521

Otherwise , if you don't hold two monotone hold cards , then the probability the flop is monotone is :

2*12c3/50c3 + 2*13c3/50c3 = 0.05163

In the former case , you need to offer him odds of (100-5.21)/5.21=18.19:1 to break even .

For the other case , you need to offer him odds of (100-5.16)/5.16= 18.37:1 which isn't much different .