All the groups have there own way of toughness. So its not like that the science is the hardest and Arts is the easiest.

I would say, the easiest subject or stream is the stream you personally are interested in. So you have to find out which you are interested in. If you are interested in knowing logical behavior and mechanism of everything, then go for Sciences. If you had interested in the dynamics and different properties of Business, then I would recommend you to go for the Commerce. Apart from this if you want to go for the realization of literature, for interpreting different aspects of life then Arts will give you the scope to do so.

For information regarding the Stream to choose after 10th consider the link below:

https://school.careers360.com/articles/which-stream-select-after-class-x

I hope this helps. Wish you a great day!