7. Suppose we wish to make a small Keplerian telescope (that can be used with a relaxed eye) out of two positive lenses with focal lengths of 6 cm and 90 cm. (a) Determine the length of the telescope, and angular magnification. (b) If we wish to see a nearby object located 20 m in front of the objective with a relaxed eye, then how far you shall pull the eyepiece out?