73 has no factors other than 1 and 73.
You cannot make 1 basket with no leftovers, since there are not 73 od the other fruits.
Similarly, you cannot make 73 baskets with one of each fruit.
So, no matter how many baskets you make with the same number of apples and oranges, there will be bananas left over.
GCF(54,36) = 18
So, you can make 18 baskets with 3 apples and 2 oranges and 3 bananas.