Help me with this answer please

From a reliable source, the maximum capacity of a standard bus used as school bus is 72 students. Because the bus that Mr. Tuttle drives is already 3/4 full, only 1/4 of the capacity is unoccupied. With this, the number of the empty seats is calculated by multiplying 72 by 1/4 as shown below.
        empty seats  = (1/4)(72) = 18

Therefore, the bus could have accommodated 18 more students.