What do CBSE Students search the most on internet for their studies?

As per guidelines, it is now optional that you want to appear for Class X Board Exam or Not. So what are you appearing for.

How many 2 element subsets does a 4 element set have?

How many 2 element subsets does a 4 element set have?

who is father of algebra? ( please click the answer of your choice, DONT add comments)

14.5 X 0.5 is how much? (try to do this one in your head instead of using paper or else everyone will get 100% and I know they may have all used paper instead).

Which among these topics is most difficult to study ?

Is trigonometry useful in practical world?