A spice recipe calls for 1/2 tsp of crushed red pepper for every 1 1/4 tsp of black pepper. You ude 3 tsp of crushed red pepper. How many tsp of black pepper do I need?

To find out how much black pepper you need, you need to determine the ratio between the amount of crushed red pepper and black pepper.

The recipe states that for every 1/2 tsp of crushed red pepper, you should use 1 1/4 tsp of black pepper. This can be written as:

(1/2 tsp red pepper) : (1 1/4 tsp black pepper)

Now, we can use this ratio to find out how much black pepper is needed when using 3 tsp of crushed red pepper.

Let's set up the proportion:

(1/2 tsp red pepper) / (1 1/4 tsp black pepper) = (3 tsp red pepper) / x

To solve for x (the amount of black pepper needed), we can cross-multiply and solve for x:

(1/2 tsp red pepper) * x = (1 1/4 tsp black pepper) * (3 tsp red pepper)

Multiply both sides by 2 to simplify the red pepper fraction:

x = (2 * 1 1/4 tsp black pepper * 3 tsp red pepper) / 1/2 tsp red pepper

Simplifying further:

x = (2 * 5/4 tsp black pepper * 3 tsp red pepper) / 1/2 tsp red pepper

Now, cancel out the tsp red pepper terms:

x = (2 * 5/4 tsp black pepper * 3) / (1/2)

Multiply across the numerator:

x = (10 * 3) / (1/2)

Divide by the denominator:

x = 30 / (1/2)

To divide by a fraction, we can multiply by its reciprocal:

x = 30 * (2/1)

Finally, multiply:

x = 60

Therefore, you will need 60 tsp of black pepper when using 3 tsp of crushed red pepper in this recipe.