Meta Data Scientist interview questions

Find all indices into an array A such that: * There are three elements (not necessarily distinct) * The three indexed elements sum to 0

There's a game where you are given two fair six-sided dice and asked to roll. If the sum of the values on the dice equals seven, then you win $21. However, you must pay $5 to play each time you roll both dice. Do you play this game? And in follow-up: What is the probability of making money from this game?