LINQ Slow Performance In Checking Almost 1 Million Or Large Data (Optimization Problem) In C#

I have a code below which returns an object after satisfying a given condition.

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result = listCountryStateCollection.Find(e => (e.CountryName.ToLower().Trim() == accomTempHotel.CityProvinceCountryName[0].CountryName.ToLower().Trim()) && (e.StateName.Trim().ToLower() == accomTempHotel.CityProvinceCountryName[0].StateName.ToLower().Trim()) && (e.SuburbCityName.Trim().ToLower() == accomTempHotel.CityProvinceCountryName[0].SuburbCityName.ToLower().Trim()));

The problem I encountered was that, it was slow in getting the desired results. After doing optimization/code checking I came up with a simple solution. The solution is not to include string manipulations in your LINQ but instead the processing should be done using variables as defined below:

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string country = accomTempHotel.CityProvinceCountryName[0].CountryName.ToLower().Trim(); string state = accomTempHotel.CityProvinceCountryName[0].StateName.ToLower().Trim(); string suburb = accomTempHotel.CityProvinceCountryName[0].SuburbCityName.ToLower().Trim(); result = listCountryStateCollection.Find(e => (e.CountryName == country) && (e.StateName == state) && (e.SuburbCityName == suburb));

Greg