20 people paid 20 per person for food and only 30% was used how much money is left over

280

Step-by-step explanation:

First determine how much was paid for food

20 dollars times 20 people

20*20 = 400

We used 30% of that

400 * 30%

Change to decimal form

400 *.30

120 was used

How much was left

400-120 = 280

280 was left