Thomas wants to use his 5.5 d reading glasses as a simple magnifier. what is the angular magnification of this lens when thomas' eye is relaxed?

Sorry, but the given info is insufficient. 
The angular magnification is the ratio of the viewing distances. 
We assume the greater viewing distance is 26 cm. 
But the nearer viewing distance depends on the focal length of Thomas's <relaxed> eye in combination with the glasses. We don't know about his relaxed eye. We'd need to know his far point. 
For instance, say his far point is 2.5 m. Then his focal length with glasses = 1/(1/2.5+6.2) m = 15.1515 cm. Magnification = 26/15.1515 = 1.716. 
If his far point is at infinity, magnification = 1.612.