Answer:
Convert 1 1/2 into a regular fraction
Because the following quantity, 1 1/2 is a mixed fraction
1 1/2 = 3/2
According to the question
The recipe for one bath call for 3/2 cups of flour
1 batch needs 3/2 cups of flour
Multiply 3 to both of the sides
3x1 batch needs 3 times 3/2 cups of flour
3 batch would need 4 1/2
B is your answer