How old is this rifle a glenfield model 15 22?

The Glenfield Model 15 is a .22 caliber rifle that was produced by Marlin Firearms, primarily in the 1970s and early 1980s. If you have a specific serial number or production year, you can better determine its age. Typically, these rifles are now around 40 to 50 years old, depending on the exact year of manufacture.