The primary characteristic of a feudal society is the exchange of land for services.
The overlord will grant the vassal a land in exchange for the vassal's services. Services like fighting beside the lord in terms of war. Vassals have their own men and since the vassal is at the service of the overlord, his men is also at the service of the overlord.
I = Prt
I: interest earned
P: principle (initial invested amount)
r: rate (percentage)
t: time in years (duration)
Most often, when letters are side-by-side this means they are all factors of each other. If something is a factor of another, then multiply them. So, 275 times 8% or 8/100 or 0.08 times 16 years is equal to $352. With this total subtract $275 from $352. The interest earned is equal to $77.
$275 * 0.08 * 16 yrs = $352
$352 - $275 = $77
I = $77
This may seem confusing when saying aloud in order of the equation, "Interest equals $352". The total is $352, the interest earned is equal to $77. Conventions and platitudes are often erroneous.
The growing season in the interior plains is going to be five to six months