Questions

A filament is a metal wire that glows when electricity is channeled into it. The filament of an electric bulb is made of Tunsten. 

Because of its high melting point and its greatest tensile strength, it makes for a good filament in light bulbs.

13 x 2 = 26 => Z (opposite side)

12 x 2 = 24 => X (opposite side)

13 x 1 = 13 => M (opposite side)

12 x 1 = 12 => L (opposite side)

A bug leakage results when a bug is detected which should have been detected in earlier builds/versions of the application.

A defect which exists during testing yet unfound by the tester which is eventually found by the tester/end-user is also called bug leakage.

A bug release is when a particular version of s/w is released with a set of known bug(s)/defect(s). These bugs are usually low severity and/or low priority bugs. It is done when the company can afford the existence of bug in the released s/w rather than the time/cost for fixing it in that particular version. These bugs are usually mentioned in the Release Notes.