If hari buys 20biscuits for Rs 200 and sells it for Rs 100 find the loss​

I’m stuck on this equation, anyone got the answer?

Create a question with this scenario you could ask that could be answered only by graphing or using logarithm. david estimated he had about 20 fish in his pond. a year later, there were about 1.5 times as many fish. the year after that, the number of fish increased by a factor of 1.5 again. the number of fish is modeled by f(x)=20(1.5)^x.

Find the interior angle of a regular polygon which has 6 sides