Which one of the followings is a triangular number?, 17, 16, 21, 28, 2, 5, Which of the following isn’t a triangular number?, 26, 27, 28, 21, 15, 10, What is the fifth triangular number?, 1, 3, 6, 10, 17, 15.

Rankningslista

Visuell stil

Alternativ

Växla mall

Återställ sparas automatiskt: ?