WAEC Agricultural Science 1996 Question 9

In an experiment to determine the percentage of humus content in a soil, the following results were obtained: mass of dish = 10 gm; mass of dish and oven-dry soil = 50 gm; mass of dish and soil after heating = 40 gm. Calculate the amount of humus in the soil sample.

1. A.10 gm
2. B.40 gm
3. C.50 gm
4. D.60 gm
5. E.90 gm.