In a cup of sugar water, sugar accounts for one tenth of sugar water. After adding 10g sugar, the sugar accounts for two eleventh of the sugar water. Raw sugar water 10g.

The calculation process is as follows:

The original ratio of sugar to water:110 ÷ (1-110) =1/9.

Now sugar accounts for 2/11÷ (1-2/1) = 2/9 of water.

Sugar increased by 2/9- 1/9= 1/9.

Sugar increased by 10g.

Water = 10- 1/9 = 90g.

Raw sugar water = 90 ÷ (1-110) =100g.

Extended data:

If there is only addition and subtraction or only multiplication and division, it is calculated from left to right. For example, 2+ 1- 1=2, first calculate the number of 2+ 1, and then subtract 1 from the number of 2+ 1.

If the first-level operation and the second-level operation exist at the same time, the second-level operation is calculated first. If there are one, two and three operations at the same time (i.e. power, root and logarithm operations), the third operation is calculated first, and then the other two levels are calculated.