Step 1: General formula of carbohydrates.
Most carbohydrates follow the general formula (CH$_2$O)$_n$. Step 2: Exception to the rule.
Some carbohydrates contain modified groups and do not strictly follow this formula. Step 3: Identifying rhamnose.
Rhamnose is a deoxy sugar in which one hydroxyl group is replaced by hydrogen. Step 4: Conclusion.
Thus, rhamnose is a carbohydrate that does not follow the general formula.