Missing number (?) in the following figure is: 2 3 5 ? 12 8 23 30 38

Question

Missing number (?) in the following figure is:
1. 15
2. 21
3. 20
4. 17

Answer 1

Correct Answer - Option 4 : 17

The logic is:

1st row: (2 + 5) - 1= 3 × 2

⇒ 7 - 1 = 6

⇒ 6 = 6

3rd row: (23 + 38) - 1 = 30 × 2

⇒  61 - 1 = 60

⇒ 60 = 60

Similarly,

Let the missing number in 2nd row be 'x'.

Therefore, (8 + x) - 1 = 12 × 2

⇒ 8 + x - 1 = 24

⇒ 7 + x = 24

⇒ x = 24 - 7

⇒ x = 17

Hence, ‘17’ is the correct answer.