Answer: 360
Step-by-step explanation:
60% means that 60/100 prefers hamburgers over pizza
You also know that 540 preferred hamburgers aka 60% of the people.
Now you just take 540 (the 60%) and divide it by 60 to get 1%. 540/60=9
9 is 1% of the total, you take 9*100 to get 100% which is 900
Take 900-540=360 to get the pizza people.