$(10$ points$)$ Bryan and Robbie each open up new bank accounts at time $0.$ Bryan deposits $100$ into his

bank account, and Robbie deposits $50$ into his. Each account earns the same annual effective interest

rate.

You are given:

The amount of interest earned in Bryan's account during the $11$ th year is equal to $x.$

The amount of interest earned in Robbie's account during the $17$ th year is also equal to $x.$

Calculate $x.$

A$.37$

B$.38$

C$.39$

D$.40$

E$.41$