Answer:
c : d : u = 8 : 6 : 27
Explanation:
Given c:d = 4:3 and d:u = 2:9, you want c:d:u.
Ratio units
To write the desired ratio, we need to convert the others so they have the same number of ratio units representing 'd'. That number can be the least common multiple of 3 and 2, which is 6. Knowing this, we can write ...
c:d = 4:3 = 8:6
d:u = 2:9 = 6:27
Then the desired ratio is ...
c:d:u = 8:6:27