The apparent magnitude (how bright an object appears to the

The apparent magnitude (how bright an object appears to the observer) is given by M=5/2log(b0/b), where b is the brightness of the object and b0 is a positive constant. A particular telescope is capable of viewing cosmic objects with apparent magnitude 25. An inferior telescope can view cosmic objects having at most apparent magnitude 18. What is the ratio of brightness detected by the first telescope compared to the second?