Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

Can you solve the below maths equation problem by replacing the question mark with the correct number?

Note: It has more than one solution.

You need to solve the below maths pyramid puzzle by replacing the question mark with the perfect numbers.

168 1 2 14 ? 2 ? ? 2 1 ?

Solve the number series riddle by replacing the question mark with the correct number ?

Can you solve this tricky maths equation problem by replacing ? mark with correct number ?

19834 -----: 187 15921 -----: 153 17561 -----: 137 13734 -----: ???