1. On January 1 of the current year, Yan purchased office equipment which cost 150,000 with an expected life of 5 years with no salvage value

2. Computer equipment costing 60,000 with an expected life of three years and no salvage value was purchased on July 1 of the current year.

Simple math, how long and how much since no salvage?

Not enough information provided. You will need to know what depreciation method is being used and what date is the adjusting entry being made.