Marcie is trying a new cookie recipe. she wants to see if the amount of baking powder she uses will make the cookies rise more. she makes three batches of cookies and changes the amount of baking powder for each batch. what two things must remain constant?

Following should not change -

a) Time and temperature at which baking is done

b) Quantity of all other ingredients

Explanation:

All other factors except the amount of baking factor must remain unchanged as only then the difference in baking due to change in amount of baking powder will be visible.

So, the temperature at which a cake is baked and the quantity of all other ingredients must remain the same.

Along with this, the time till which baking is done must also be constant.