Find the missing number from the following given options:

The correct answer is option 4: 36

Inside number = (Top left × Top right × Bottom number) ÷ 10

For the 1st triangle: ⇒ \(\frac{6 × 7 × 5}{10}\) = \(\frac{210}{10}\) = 21

For the 3rd triangle: ⇒ \(\frac{50 × 10 × 10}{10}\) = \(\frac{5000}{10}\) = 500

Applying the same rule to the 2nd triangle: ⇒ \(\frac{15 × 6 × 4}{10}\) = \(\frac{360}{10}\) = 36