I know the right answer but WHY is it the right answer?

You are the project manager of a project to widen a $10$ mile section of a freeway. The approved budget is $$50$ million, and the approved schedule is $40$ weeks. After $22$ weeks, your team has completed $6$ miles of freeway and $$32$ million has been spent. What is the estimate to complete?

A$.21\mathrm{.}33$M $-$ This is the right answer but why is it the right answer?

B$.53\mathrm{.}33$M

C$.20\mathrm{.}25$M

D$.23\mathrm{.}33$M