Leakage removes shots from the readout budget before any assignment happens, so a higher leakage fraction directly cuts the retained count. The scan takes 100 input shots (80 zero, 20 one) through leakage fractions 1/10, 1/5, and 3/10, leaving 90, 80, and 70 retained shots exactly for the stated ideal ledger; real systems add calibration drift, leakage variability, readout noise, and finite-count statistics.
Leakage is easier to audit when the lost fraction is scanned across exact rows. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
One tenth leakage keeps ninety shots
The input ledger is 80 zero and 20 one. With leakage fraction 1/10, the lost row is 8 plus 2, so 90 shots remain for readout.
8+2=10,Nkept=90
One fifth leakage is the original audit row
At leakage fraction 1/5, the kept counts are 64 zero and 16 one, while lost counts total 20.
64+16=80,Nlost=20
Three tenths leakage leaves seventy shots
Increasing leakage to 3/10 gives lost counts 24 and 6. The retained readout budget falls to 70 shots.