Combinatorics is a branch of mathematics dealing with issues of order and choice.

I love mathematics.

Discrete mathematics is an important field that forms the basis of computer science.

He is majoring in applied mathematics at university.

He is passionate about researching pure mathematics.

He is a world-famous mathematician.

Combinatorics is a branch of mathematics that studies combinations of things.

Combinatorics is a branch of mathematics that studies combinations of things.

He made a selection from the menu.

He is working in the field of science.