Write each of these numbers in factored form:
144 = 2^4 x 3^2
108 = 2^2 x 3^3
90 = 2 x 3^2 ^ 5
The greatest common factor is 2 x 3^2 = 18
So, you can make 18 baskets:
each will have 8 apples, 6 pears, and 5 oranges.