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

Explanation

Explanation

The pattern adds 4 each time:

3 + 4 = 7

7 + 4 = 11

11 + 4 = 15

Last verified on 11-07-2026

Explanation

Pattern: n + n = 2 × n²

2 + 2 = 2 × 2² = 2 × 4 = 8

3 + 3 = 2 × 3² = 2 × 9 = 18

4 + 4 = 2 × 4² = 2 × 16 = 32

5 + 5 = 2 × 5² = 2 × 25 = 50

Verified & Updated

Explanation

The pattern is:

• $5 times 2 + 1 = 11$
• $11\times 2+1=23$
• $23\times 2+1=47$
• $47\times 2+1=95$

Answer: 95

Last question by NA on 09 July 2026

Explanation

Find the difference between terms:  

10 - 2 = 8  

20 - 10 = 10  

38 - 20 = 18  

64 - 38 = 26  

Differences: 8, 10, 18, 26  

Now find difference of differences:  

10 - 8 = 2  

18 - 10 = 8  

26 - 18 = 8  

Next difference increases by 8 again  

So next difference = 26 + 8 = 34  

Next term = 64 + 34 = 98

Last verified on 09-07-2026

Explanation

The differences are increasing by 2:

6 → 11 (+5)

11 → 18 (+7)

18 → 27 (+9)

So the missing number is 18.

Last verified on 17-06-2026

Explanation

Look at the pattern: each term × 3  

2 → 6 → 18 → ? → ? → 486  

So 18 × 3 = 54

54 × 3 = 162  

162 × 3 = 486  

Full sequence: 2, 6, 18, 54, 162, 486  

Now "4th term from the last"  

Last = 486, 2nd last = 162, 3rd last = 54, 4th last = 18.

Last verified on 24-06-2026