$18.25 is the hourly rate because half of $12.50 is $6.25 and if you add that you will get the hourly range which is $18.25.So 18.25 is 1 and 1/2 of $12.50.
First you would divide 45 by 9 to see how many times it will double which gives you 5. Then, you would multiply 2000 by 2^5 (or just 2000x2x2x2x2x2) to get $64000
