Basically, you're going to use the amount of (0s) and the number 7 to your advantage.
You know it's going to be 00007 (or 7) out of something.
So, 7/?
7/10 = 0.7
7/100 = 0.07
Just keep adding 0s.
7/1000 = 0.007
7/10000 = 0.0007
and finally,
Your Answer:
7/100000 = 0.00007
