Answer:
8 units.
Explanation:
The complete question is
A scale factor of 1/3 is used to make a reduction, as shown in table below.
What is the base of the reduced triangle?
According to the given table, the original base is 24. If the given scale factor is applied, the reduced base would be

Remember that a scale factor is a number that multiples the figure, a scale factor can reduced or amplify a figure.
Therefore, the reduced base is 8 units.