Total amount of mixed ingredients needed to make one batch = 23/24 teaspoons For one batch of biscuits and gravy, the amount of ingredients required is:
1⁄2 teaspoon of salt,
1⁄3 teaspoon of oregano; and
1⁄8 teaspoon of black pepper
which makes a total of (1/2) + (1/3) + (1/8) = 23/24 teaspoons.
Now, Richard is making 'two' batches of biscuits and gravies so he would need double of the amount of ingredients that he used before for making one batch, But, since the question asks for the total amount of mixed ingredients for one batch so it will be 23/24 teaspoons.