Python for Everybody 3.1 assignment

[Incubroz]

Hello all

I see that a working codehas already been posted but I'm trying to resist just copying somebody else's work. However, I'm getting a headache staring at this now!
I'm a total beginner, admittedly but it's frustrating me that I'm getting stumped so early on in this course.
With the below code, I'm not getting any errors, it's a perfectly good, working code.
The issue is that I should be able to input:
Hours 45 (sth)
Rate 10.50 (str)
...and come out with an answer of 498.75
My code is coming up with 551.25 !

I'm sure it's something really simply that I'm overlooking because I've been staring for too long but can anyone spot it?

sth = input("Enter hours: ")
str = input("Enter rate: ")
flh = float(sth)
flr = float(str)
if flh > 40 :
    reg = flr * flh
    ot = (flh - 40.0) * (flr * 1.5)
    pay = reg + ot
else:
    pay = flh * flr
print (pay)