Question

If a buyer purchases 25% of a lot in the spring and then purchases 50% more later in the fall, what percentage of the lot is still available for purchase?

Answer 1

Let
T--------> the total of the lot

we know that
a buyer purchase=0.25T+0.50T------> 0.75T

 lot still available for purchase=T-[0.75T]-----> 0.25T
T----------> 100%
0.25T----> x
x=0.25T*100/T------> x=25%

the answer is
25%