Find the fourth proportional to 20, 24 and 30.

Correct option is A

Given:
Numbers: 20, 24, 30
Formula Used:
If a : b = c : d then d = $$\frac{b × c} a$$​​
Solution:
​$$d = \frac{24 \times 30}{20} \\\ \\= \frac{720}{20} \\\ \\= 36 \\\ \\\therefore \text{Fourth proportional} = 36 \\\ \\$$​​
Exam Hall Method: