Final answer:
To find the volume of the trailer in Alfie's model, convert the scale from meters to centimeters. Then, multiply the real volume by the scale factor cubed to get the volume in the model.
Step-by-step explanation:
To find the volume of the trailer in Alfie's model, we need to convert the scale from meters to centimeters. Since 1 meter is equal to 100 centimeters, the scale of 1:72 means that 1 centimeter in the model represents 72 centimeters in real life.
To convert the volume from cubic meters to cubic centimeters, we need to multiply the real volume by the scale factor cubed (72³). The volume of the trailer in real life is 90 cubic meters, so the volume in Alfie's model is 90 * (72³) cubic centimeters.