Answer:
x=21.4968
Step-by-step explanation:
You can convert this into algebra. 50/78 = 78/x
when you solve for x you get the answer.
The most likely answer is b
Take your original equation 
and multiply both sides by
to remove the fractions. You are left with

So, 
Update: There is no numerical answer that can be found without being given a value for either x or y
<span>"Chisel a whittle off the top, please."</span>
33 and one third as a fraction would be either 33 1/3 or 100/3