Explanation

Series: 5, 16, 49, ?

Check the pattern:

5 _ 3 + 1 = 15 + 1 = 16

16 _ 3 + 1 = 48 + 1 = 49

Rule: Multiply by 3 and add 1

Next term:

49 * 3 + 1 = 147 + 1 = 148

Next number = 148

Last verified on 12-07-2026

Explanation

Pattern: Multiply by 2 and add 3.

7 × 2 + 3 = 17

17 × 2 + 3 = 37

37 × 2 + 3 = 77

77 × 2 + 3 = 157

Last verified on 12-07-2026

Explanation

The pattern increases by 4 each time:

8 → 12 (+4)

12 → 16 (+4)

The next number should be 20, not 21.

Therefore, 21 is the incorrect number.

Last verified on 12-07-2026

Explanation

Look at the pattern:

1 + 2 = 5  

1 square + 2 square = 1 + 4 = 5

2 + 3 = 13  

2 square + 3 square = 4 + 9 = 13

3 + 4 = 25  

3 square + 4 square = 9 + 16 = 25

So the rule is: a + b = a square + b square

Now find 4 + 5  

4 square + 5 square = 16 + 25 = 41

Last verified on 12-07-2026

Explanation

Pattern: Multiply by 2 and add 1

1  

3 = 1 x 2 + 1  

7 = 3 x 2 + 1  

15 = 7 x 2 + 1  

31 = 15 x 2 + 1  

63 = 31 x 2 + 1  

? = 63 x 2 + 1 = 127  

Last verified on 11-07-2026