Find the number that goes in the empty box.

The correct answer is: 15

Step 1 of 2:
Given that, for x = 0, y = 5; for x = 5, y = 10; for x = 15, y = 20; for x = 20, y = 25; for x = 25, y = 30.
Observe that, y - x = 5 for all cases. So, y = x + 5.
Step 2 of 2:
So, the table uses the pattern add 5.
Hence, for given x = 10, we get y = 10 + 5 = 15.
Final Answer:
The right choice is-- d. 15