Given :
Heidi uses 5 grams of tea leaves to make 25 fluid ounces of tea.
Last week she made 75 fluid ounces of tea.
To Find :
How many grams of tea leaves did Heidi use to make tea last week.
Solution :
Let, x gram of leaves are required last week.
So,

Therefore, 15 grams of tea leaves is used last week.
Hence, this is the required solution.