ANSWER
6
Step-by-step explanation
We have the ratio table given.
Let the missing number be x.
From the table, we see that the ratio is:
3 : 15 = x : 30 = 18 : 90 = 24 : 120
So, we can pick one group of ratio to compare with the group of the missing number.
That is:
So, the missing number is 6.