1let traveler = [{"description":"Senior","Amount":50},{"description":"Senior","Amount":50},{"description":"Adult","Amount":75},{"description":"Child","Amount":35},{"description":"Infant","Amount":25}]
2
3let result = traveler.reduce((c, v) => {
4  c[v.description] = (c[v.description] || 0) + v.Amount;
5  return c;
6}, {});
7
8console.log(result);