Gate 2017 Q53. The average assay (a) and area of influence (A) of a placer gold deposit of uniform thickness sampled at four locations W,X,Y and Z are given below. The weighted average assay of the ore body is ___________ g/t.

 Gate 2017 Q53.

The average assay (a) and area of influence (A) of a placer gold deposit of uniform thickness sampled at four locations W,X,Y and Z are given below. The weighted average assay of the ore body is ___________ g/t.

Solution:-   Weighted average assay value would be given here

\[Avg Assay = \frac{\sum ai.Ai}{\sum Ai}\]

ai = Individual assay values of a location i

Ai = Area of location i

\[Avg Assay = \frac{\left ( 28\times 40+12\times 28+30\times 23+15\times 25 \right )}{40+28+23+25}\]

\[\large Avg Assay = \frac{2521}{116}\]

\[\large Avg Assay = 21.73\]