An oil drilling company purchased an equipment for 300,000. It is estimated that the equipment will have a salvage value of 30,000 after 5 years of usage. If capital is worth 10 %, determine the equipment's book value after 3 years using the following methods: (a) SL method, (b) SFF method, (c) DB method, (d) SYD method,(e) DRDB method.