Shelley delivered 12 newspapers after 20 minutes and 36 papers after 60 minutes what is the independent variable and the dependent variable and what is the rate of exchange

The rate of exchange is 8%

Step-by-step explanation:

Given as :

Shelley delivered 12 newspaper after  20 min

And She delivered 36 papers after 60 min

Let the exchange rate = R %

So,

     Final value = Initial value ×  ( 1 + )

Or, 36 × 60 =  12 × 20 ×  ( 1 + )

Or,  2160  = 240 ×  ( 1 + )

Or,   =  ( 1 + )

Or,   9   =  ( 1 + )

∴     = 9 -1 = 8

Or , Rate = 8%

Hence The rate of exchange is 8%   Answer