Multiple choice
Run this circuit, then measure all 2 qubits at once. What is the probability of the joint outcome |10⟩ (qubit 0 leftmost)?
// Start at |00>, flip qubit 1 to get |01>, Hadamard qubit 0 to get // (|01> + |11>)/sqrt(2), then CNOT(0->1) turns |11> into |10>, giving // the symmetric triplet (|01> + |10>)/sqrt(2). const c = circuit(2); c.x(1); c.h(0); c.cx(0, 1); return c;
Commit your prediction for P(|10⟩) — then run it.