Answer: 3: 5: 9 Step By Step Answer: The given ratio is 18 : 30 : 54 Rewrite this ratio by writing the factors of each terms as shown below 6×3 : 6×5: 6×9 Now, 6 is common in all the three factors. hence, we can cancel it and we are left with 3 : 5 : 9 Now, there is no any common term. Hence, we can't simplify the ratio more. Therefore, the required ratio is 3 : 5 : 9