1. What is a closure?

2. You are given two jugs with capacities x and y litres. There is an infinite amount of water supply available. You need to determine whether it is possible to measure exactly z litres of water using these two jugs. If such a combination exists, return true; otherwise, return false.

3. Have you dealt with large data sets in any of your projects?

4. Why is discounting a way to incentivize inactive customers?

5. For each element in an array, find the sum of the smallest element to its left and the largest element to its right.