Q:

A corn field has an area of 80,000 square feet. A new parasite has caused the area of the corn field to decrease by one-fourth each month. Which equation can be solved to determine the number of months, t, when the area of the corn field is 33,750 square feet, and how long will it take?

Accepted Solution

A:
1/4 = 25% so the field would be 75% as much each month

 the equation would be something like:  80000*0.75^x 
 You didn't list the choices....

solve for time: 33750 = 80000*0.75^t
                        0.4219 = 0.75^t
                       
t = log(0.4219) / log(0.75)
 time = 3 months