5:35 A firm buys Rs. 10,000 worth of plant on January 1, 1939. and arranges for depreciation according to the following schedule : Caregory Cost (Rs.) Depreciation rate General Plant 4,000 5% on reducing balance Electrical Plant 1,000 7.5% Process Plant 3,000 Lorries 2,000 20% Find the average depreciation rates for 1939 and 1940. Give reasons for the difference between the two averages. 99 10% 9 > 99