Here's why:

* Solubility: Salt is more soluble in water than sugar. This means that at a given temperature, more salt can dissolve in water than sugar.

* Temperature and Solubility: While both salt and sugar solubility increase with temperature, sugar's solubility increases much more dramatically. This means that while both substances dissolve faster in warm water, the difference is much more pronounced for sugar.

Here's a breakdown:

* Cold water: Sugar dissolves at a noticeable rate in cold water, while salt dissolves relatively slowly.

* Warm water: Both sugar and salt dissolve faster, but the difference in solubility is much more significant for sugar.

Therefore, sugar dissolves faster in cold water than salt.