Which set should you open first?
If you are starting cold, open an easy 5-minute practice set. If you already have rhythm today, choose a medium 10-minute practice set. If you want the closest rehearsal for the real SSC CGL DEST, open a 15-minute mock test with the stricter exam-style layout.
Official SSC notices describe the DEST as a 15-minute qualifying test for about 2000 key depressions, with additional time only for eligible PwBD candidates using a scribe or compensatory time.
Best for weekdays
Easy or medium practice sets usually give the best balance between useful reps and not frying your patience.
Best for exam feel
Use the 15 minute mock when you want the closest feel to the official SSC DEST window of about 2000 key depressions and less help on screen.
Best for stamina
Move to 15 or 30 minutes only after shorter runs stop feeling chaotic. For real exam rehearsal, the 15 minute mock is the one that matters first.