In a stack of cards, 8 cards are blue and the rest…

In a stack of cards, 8 cards are blue and the rest are red. If 2 cards are to be chosen at random from the stack without replacement, the probability that the cards chosen will both be blue is 1/2. What is the number of cards in the stack?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #49742