The term carbohydrate can basically be translated into "carbon water".

Therefore, the typical formula for a carbohydrate is #CH_2O#. --> Carbon with 2 Hydrogen and 1 Oxygen: #C + H_2O#

The most common sugar is glucose from the photosynthesis reaction. Glucose has a formula of #C_6H_12O_6#. Sucrose which is table sugar is #C_(12)H_(22)O_(11)#. Note that in each case the hydrogen is twice the oxygen, just the same as in a water molecule.