Consider the scenario involving Ri = 1 at which point the grade of the tailings stream must be zero so Equation 1 simplifies to Y = GF/GP. This means we now consider the simpler Monte-Carlo analysis of the feed grade distribution being divided by the product grade, both with random errors. Careful application of the Monte-Carlo approach, ensuring use of a normal distribution with common relative uncertainties for the two stream assays, reveals a unique error amplification of ~ 2 0.5 . This simple scenario of the ratio of two assays involves the summation of only two input variances; hence the final uncertainty involves an increase in the standard deviation by a factor of 2 0.5 . Thus, the error amplification at Ri -Y = (1 -Y)