Ten fish receive 15 grams of food in total when every fish gets the same portion. Which total gives 16 fish that same portion?

Explication

Each fish receives 15 divided by 10, or 1.5 grams, so 16 fish receive 24 grams altogether. Giving 21 grams by adding the six extra fish to the original total treats each added fish as one gram rather than keeping the 1.5 gram portion fixed.