Find the annual interest rate. I = $24, P = $400, t = 2 years

The annual interest rate is _% ?

The key technological innovation that brought Barack Obama to the White House wasn’t his tweets or a smartphone app. It was the Obama campaign’s novel integration of e-mail, cell phones, and websites. The young, technology-savvy staffers didn’t just use the web to convey the candidate’s message; they also enabled supporters to connect and self-organize, pioneering the ways grassroots movements would adapt and adopt platforms in the campaign cycles to come.

He do red hot so thx no us to

Google it that might work