Community mocks

Viluxent Set 1 Paper 2 · Q6

Paper 2Number & countingAlgebra

Quadratic Chase is a single-player game. To start the game, the player chooses two distinct nonzero integers aa and bb and writes the equation x2+ax+b=0x^2+ax+b=0 on a blackboard.

On each turn, if the equation currently written on the blackboard has two distinct nonzero integer solutions x=ux=u and x=vx=v, then the player erases the equation and replaces it with one of the equations x2+ux+v=0x^2+ux+v=0 and x2+vx+u=0x^2+vx+u=0, of their choosing. Otherwise, the game ends.

There is exactly one initial choice of (a,b)(a,b) for which the game can be played forever. For this pair, find the value of a+ba+b.

A−3-3
B−1-1
C00
D11
E33
FNo such pair exists

Read the questions freely. Sign in to check your answer, see the worked solution and save your progress.