Well, I'm confused now with what you want, but here is the math for the average grade over a 150m interval that is 100g/t over 5m and 1g/t over the othe 145m.

5/150 x 100 + 145/150 x 1 = 4.3g/t

Simple weighted average calculation. Now....what was the point of this? :-)

~snezzer