A set consist of 2k-1 element

A set consist of 2k-1 element. What is the number of subsets of this set which contain at most k-1 elements?

~8 minAnswer checked instantly

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #18649

Stuck? A gentle nudge

No hints for this one.

Something off?

Workspace

Your answer

Checked against the answer in AQuA-RAT.