I'm sorry if it's wrong.
Answer:
55
Step-by-step explanation:
Step 1: The last digit of the cube number from the right side is 5 that we consider 125 = 53 we put down 5. Then
Step 2: Take the number whose cube is nearest to 166. That is 166 is nearest to 53 and 63 we take small one cube digit that is 5.
So the answer is 55