Question

What should come at the place of question mark? 3, 4, 13, 14, 45, 46, ?

• A. 143
• B. 136
• C. 140
• D. 138

Answer 1

Answer:

A. 143

Observe the pattern:

• $(3 \to 4) : (3+1=4)$

• $(4 \to 13) : (4 \times 3 + 1 = 13)$

• $(13 \to 14) : (13+1=14)$

• $(14 \to 45) : (14 \times 3 + 3 = 45)$

• $(45 \to 46) : (45+1=46)$

So the pattern alternates between:

1. Add 1

2. Multiply by 3 and add increasing odd numbers ((1,3,5,\dots))

Next step:

• $46 \times 3 + 5 = 138 + 5 = 143$

So, the missing number is 143.