Step-by-step explanation:
Selling Price (SP) = Rs. 725
profit rate (P%) = 15 %
Now
Cost Price (CP)

3420°
explanation:
the equation of the sum of interior angles are (n-2)x180
polygon above has 21 sides so you sub n as 21 and plug the equation in the calculator
At the end of the year, Juan has 52.71 more than 4 times his balance at the beginning. Okay, let's set this up.
4x + 52.71
(4 times) (52.71 more)
His ending was 172.90, so
4x + 52.71=172.90
4x= 120.19
x= 30.05
He had $30.05 at the beginning of the year.