Final answer:
To ensure everyone gets enough, the fifth graders should order 17 pizzas, which will cost $204.
Step-by-step explanation:
To ensure that each student gets at least two slices of pizza, we need to calculate the total number of slices required. With 65 students and each student getting 2 slices, the total number of slices needed is 65 x 2 = 130 slices.
Since each pizza has 8 slices, the number of pizzas required can be determined by dividing the total number of slices needed by the number of slices in each pizza. 130 slices / 8 slices per pizza = 16.25 pizzas.
Since we can't order a fractional number of pizzas, we need to round up to the nearest whole number. Therefore, the fifth graders should order 17 pizzas to ensure everyone gets enough.
The cost of each pizza is $12, so multiplying the number of pizzas by the cost per pizza gives us the total cost: 17 pizzas x $12/pizza = $204.