i) \(1, 2, 3, 4, 5, 6, \dots\) (Natural Numbers)
Pattern: Add \(1\) to the previous term.
Next terms: \(6+1=7,\; 7+1=8,\; 8+1=9.\)
Ans: 7, 8, 9
ii) \(1, 3, 5, 7, 9, 11, \dots\) (Odd Numbers)
Pattern: Add \(2\) to the previous term.
Next terms: \(11+2=13,\; 13+2=15,\; 15+2=17.\)
Ans: 13, 15, 17
iii) \(1, 3, 6, 10, 15, 21, \dots\) (Triangular Numbers) [cite: 121]
Pattern: Add consecutive natural numbers \((+2, +3, +4, \dots)\).
Next terms: \(21+7=28,\; 28+8=36,\; 36+9=45.\)
Ans: 28, 36, 45
iv) \(1, 4, 9, 16, 25, 36, \dots\) (Square Numbers) [cite: 121]
Pattern: Squares of natural numbers (\(n^2\)), or add consecutive odd numbers \((+3, +5, +7, \dots)\).
Next terms: \(7^2=49,\; 8^2=64,\; 9^2=81.\)
Ans: 49, 64, 81