C# Looping through Dictionary and summing values for Keys -

i have dictionary<string, decimal?>, , able sum decimals distinct string. have below inputs in dictionary,

"1", 20.00 "1", 35.00 "2", 10.00 "3", 15.00 "3", 30.00

i following output new dictionary

"1", 55.00 "2", 10.00 "3", 45.00

i'm guessing

foreach(var item in dictionary) { newdictionary.add(not sure go here, maybe sort of linq query distinct , sum?); } 

the keys in dictionary can't repeated, 2 first entries won't fit in dictionary.

i think may have list of objects can loop, can use dictionary store total each "key"

something like

 dictionary<string, double> totals = new dictionary<string, double>();         list<tuple<string, double>> entries = new list<tuple<string, double>>() {             new tuple<string, double>("1",20.00),             new tuple<string, double>("1",35.00),             new tuple<string, double>("2",10.00),             new tuple<string, double>("3",15.00),             new tuple<string, double>("3",30.00)         };         foreach (var e in entries)         {             if (!totals.keys.contains(e.item1))             {                 totals[e.item1] = 0;             }             totals[e.item1] += e.item2;         }