DataScience.com Data Science(DS12) interview questions

I applied online. I was to give a Mathematical assessment(most of them are statistics based) and then after a programming assessment which was like HackerRank and questions were Medium to Hard.I was contacted by 2 people for an interview on bluejeans where they went over my resume, experience, projects and interviewed on Machine Learning and Statistics. Everything went well and they gave me an offer for an internship which was contingent upon learning Scala in 3 weeks after which an interview was taken and since I couldn't reach their expectations in Scala they took back the offer. One among the interviewers was nice and calm encouraging me to answer the questions and the other was not so well. He was concentrating more on statistics and throughout the interview gives an opinion as if I didn't know anything.