I need help with this question???

On a piece of paper graph f(x)=5•(0.4)^x

The temperature of chicken soup is 192.7°f. as it cools, the temperature of the soup decreases 2.3°f per minute. what is the temperature in degrees fahrenheit of the soup after 25 minutes? a. 27.3°f b. 57.5°f c. 135.2°f d. 250.2°f

Acabinmaker buys 3.5 liters of oat varnish the varnish cost $4.95 per liter what is the total cost of 3.5 liters