Which of the following is / are true about weak learners used in ensemble model?1. They have low variance and they don’t usually overfit2. They have high bias, so they can not solve hard learning problems3. They have high variance and they don’t usually overfit

Machine learning (ML) is a branch of artificial intelligence that leverages data to improve computer performance by giving machines the ability to "learn", or improve performance — based on the data.

There are four basic approaches to machine learning: supervised learning, unsupervised learning, semi-supervised learning and reinforcement learning.