# Practo Interview Questions – Set 1

I recently got an offer from Practo, here is my interview experience:

There were four rounds.

Round 1:

Coding Test on HackerRank.

Round 2:

Q1. Implement queue with the help of two stacks.
Q2. Given a table “student” of with columns Name and Marks. You have to write a SQL query to get the 2nd highest marks from the table. Also write a query to find the nth highest marks, where n can be any number.
Q3. What is left join. Give example. And Full outer join?

Round 3:

Q1. Given three arrays sorted in non-decreasing order, print all common elements in these arrays.
Examples:
ar1[] = {1, 5, 10, 20, 40, 80}
ar2[] = {6, 7, 20, 80, 100}
ar3[] = {3, 4, 15, 20, 30, 70, 80, 120}
Output: 20, 80
Q2. A puzzle. You will be given with a 3 Litre container & a 7 Litre Container. Measure exactly 5 Litres of water.

Round 4:

Q1. Asked about one of my projects I mentioned in my resume?
Q2. Find if a number is a power of 2 or not?

Overall it was a very good experience. They test you from every aspect. In the End I would like to say that Practo is one of the best companies to work for.