Standard info :
Telephonic Interview

Introduction: 5 min.
Coding challenge: 35/40 min.
Followup questions: 5/0 min.

Tip: Remember that the interviewer is ready with 2 questions but you don't have to crack both of them if the first question is long.
Example : My previous screening round (years ago)had just one question. And I went ahead to onsite round. So, don't be discouraged if you solve just one and it is long/hard solution.
My 2 years ago question was : Integer to English word. I went to the Fb office to do it inperson and the question is not hard but just very long to write on whiteboard. And I cleared the round with positive feedback

Okay, to the current question:
Question 1 : It was linked list question. Same as this with some backstory : Next Greater Node In Linked List
Question 2: It was in the following lines:
Given an n-ary tree, which has some coins in the tree nodes.
Your job is to report the amount of steps needed to gather(and come back) all the coins, once the map is "known".
Each edge takes E steps to walk :
So, for a simple tree :

A,B, C, F, G has no coins. Represented by X.
E, D has coins. Represented by Y.
So, you would want to walk the blue edges to get the answers. Multiple by E.
So, if E is 2 this is 6*2 = 12 steps. Answer is 12. (8 for left and 4 for right)

Happy Coding!