Please help new to excel and I cannot average elapsed time columns-see attached

[Borko]

I am new to excel and I cannot average the elapsed time columns--please help

[JieJenn]

If you're using excel 2010, you can eliminate error by using IFERROR Function. Try this formula to see if it helps.

=IFERROR(TEXT(D2-E2, "dd h:mm:ss"),"")