Very few people pass in the minimum number of hours, although definitely possible, I have only come across about 2 or 3 that passed with less than 50 hours.
If you meant 45 hours FROM NOW, as in excluding the previous hours - solely depend on your personal aptitude and dedication of time and effort, in addition to frequency of lessons (with enough reflexion time).
The blocks of time you state seem to be relatively small chunks, and although you may very well be able to fly straight and level, climb and descend, even perhaps make rate 1 turns in both directions, I assume that you did not go solo / did much circuit (or radio) training (which for most, seems to be the first major hurdle.). So that is definitely something to bear in mind.
Your instructor will be able to let you know how you are progressing, and how you are coming along after a few lessons, and if he / she is very experienced, may even be able to shed some more light on timings! But take these with a pinch of salt, no two students are the same, and hence no two students struggle on the same parts of the syllabus in the same way! :-)
Keep us posted on your flying adventures!!!
Alex