Since the profit in the first week is $70
Since it increases by $15 each week, then
We can solve it as an arithmetic progression
P = a + (n -1)d, where
a is the profit in the 1st week
d is the value of increasing each week
n is the number of the week
a = 70, d = 15, and n = 12 (12th week)
Substitute these values in the rule above
P = 70 + (12 - 1)(15)
P = 70 + 11(15)
P = 70 + 165
P = 235
The profit during the 12th week is $235
