Answer: The surface area is reduced by a factor of 16/25
Step-by-step explanation: The area is the square measurements. So squaring the factor of the linear measurement change is the quick way is to determine the factor for the area.
The longer way-- if you had to prove your conclusion:
Compute the area of each side, add all the five sides of the prisms and find the ratio.
The area of the large prism is 500 square units.
The area of the smaller prism is 320 square units
320/500 = 32/50, reduce again 16/25
