Puzzle 1:- What number should replace the question mark?
Ans:-0.
Sol:-Looking at lines of numbers from the top : 9×8 = 72; 72×8 = 576; 576×8 = 4608.
Puzzle 2:- What number should replace the question mark?
Ans:-17.
Sol:-It is the sum of the two digits(9 + 8) in the quadrant opposite.
Puzzle 3:- What number should replace the question mark?
Ans:-55.
Sol:-Each number indicates its position in the grid.55 indicates row 5 columns 5.
Puzzle 4:- What number should replace the question mark?
Ans:-19.
Sol:-As you move diagonally down, numbers follow the sequence of Prime Numbers.
Puzzle 5:- What number should replace the question mark?
Ans:-16.
Sol:-Starting bottom left and moving clockwise around the triangle, numbers follow the sequence of Square Numbers.