Ответ:

--- PascalABC.NET 3.6.2 ---

#1

begin

 var A := ArrRandom(70, -99, 99);

 A.Println;

 A.Where(p -> (Abs(p).ToString.Length = 2) and (p mod 10 = 3)).Aggregate(BigInteger.One, (p, q) -> p * q).Println;

end.

#2

begin

 var A := ArrRandom(70, -999, 999);

 A.Println;

 A.Where(p -> (Abs(p).ToString.Length = 3) and (p mod 5 <> 0)).Average.Println;

end.

Объяснение:

begin

 // 1

 var n := ReadInteger('n =');

 var a := ArrRandom(n, -150, 150);

 a.Println;

 a.Where(p-> Abs(p) in 10..99).Product(p-> BigInteger(p)).Println;

 // 2

 var b := ArrRandom(n, -150, 150);

 a.Println;

 a.Where(p -> (Abs(p) in 100..999) and (p mod 5 <> 0)).Average.Print;

end.