Answer: A 
Explanation: using the common ratio we can solve this. 24:8 = x:4 
24 divided by 8 is 3. 
Therefore x divided by 4 should be 3 too. 
4 multiplied by 3 is 12, so x = 12.
For y:
When triangles are similar, the angles are always the same. So y is simply 40 degrees.