Problem: At the start of its business, Snell Corp. decided to use the composite method of depreciation and prepared the following schedule of machinery owned.
Total Estimated Estimated Life
Cost Salvage Value in Years
Machine A $275,000 $25,000 20
Machine B 100,000 10,000 15
Machine C 20,000 -- 5
Snell computes depreciation on the straight-line method. Based on the information presented, the composite life of these assets (in years) should be?