Question

Find the missing number:

$4,10,23,50,105,?$

• A. $215$
• B. $210$
• C. $216$
• D. $439$

Answer 1

The correct option is C $216$

Option (C) is the correct answer
Explanation:
In the following series the number is multiplied by two and added by 2,3 ... by number increasing by 1 to form the next number

$4\times 2+2=10$

$10\times 2+3=23$

$23\times 2+4=50$

$50\times 2+5=105$

Hence next number following the series will be

$105\times 2+6=216$