(names, ages) = persons.SelectMany(x => (n, a), n.Distinct(name), a.Distinct(a.age));

var list = new List<(string name, int age)> { ("1", 2), ("3", 4) };

var data = list.Aggregate(
    (names : new HashSet<string>(), ages : new HashSet<int>()),
    (seed, item) =>
    {
        seed.names.Add(item.name);
        seed.ages. Add(item.age);
        return seed;
    });

IEnumerable<IEnumerable<T>> Transpose1<T>(IEnumerable<IEnumerable<T>> list) {
    return 
        list.First().Any()
            // generate list of heads of lists   | 'concat' it with the rest of the matrix transposed
            ? (new []{list.Select(x => x.First())}).Concat(Transpose1(list.Select(x => x.Skip(1))))
            : (IEnumerable<IEnumerable<T>>) new List<List<T>>();
}

(names, ages) = ((from p in persons select p.name).Distinct(), (from p in persons select p.age).Distinct());

S>(names, ages) = persons.SelectMany(x => (n, a), n.Distinct(name), a.Distinct(a.age));
S>

public IEnumerable<T> Distinct<T>(this IEnumerable<T> source) => 
  source.Aggregate(new ImmutableHashSet<T>(), (set, x) => set.Add(x));

(names, ages) 
  = persons.Aggregate(
    (names: new ImmutableHasSet<string>(), ages:new ImmutableHashSet<int>()), 
    (acc, person) =>(acc.names.Add(person.name), acc.ages.Add(person.age))
  );