Final answer:
There are 54 seats on the left side of the airplane. This is calculated by first determining the number of rows, which is 18, and then multiplying by the 3 seats per row on the left side.
Step-by-step explanation:
The question is asking how many seats there are on the left side of the airplane, given that there are 72 seats on the right side. Each row has 3 seats on the left side and 4 seats on the right side. If there are 72 seats on the right side, and each row contributes 4 seats to this total, we can find the number of rows by dividing 72 by 4.
72 ÷ 4 = 18 rows
Now that we know there are 18 rows, we can calculate the number of seats on the left side by multiplying the number of rows by the number of seats in each row on the left side.
18 × 3 = 54 seats on the left side