Diana uses 30 grams of coffee beans to make 48 fluid ounces of coffee. How many grams of coffee beans foes Diana uses when company comes?

We know that

If Diana uses 30g to make 48 fl oz

then

she made 48gloz/30g=1.6fl oz/g

If she wants to make 100 fl oz

1.6 fl oz/g*x grams=100 fl oz

x=62.5 grams

the answer is

Diana needs to use 62.5 grams of coffee beans to make 100 fl oz of coffee