Answer:
if 4x square is the question the answer will be 144 or if 4x multiply by 2 then the answer will be 24
My drawing represents 37 - 19.
The red is the leftover when you subtract.
The blue is what you took away when subtracting.
I drew 37 red circles and then took away 19 circles by coloring them blue. You are left with 18 red circles.
4000000/6000=666.67
(1+r)^200=666.67
ln (1+r)^200=ln 666.67
200 ln (1+r)=ln 666.67
e^ln (1+r)=e^.03251145
1+r=1.0330457
r=0.0330457, or 3.30457% APR