Arecipe calls for 2/5 cup of sugar for every 8 teaspoons of vanilla. what is the unit rate in teaspoons per cup ?

For 2/5 cup, vanilla needed = 8 teaspoons
so, for 1 cup, it would be: 8 / 2/5
⇒8 × 5/2
⇒40/2
⇒20

In short, Your Answer would be 20 teaspoons

Hope this helps!

8 teaspoons would be needed for  2/5 cup.

Ratio of teaspoons to cup =  8 teaspoons / (2/5) cups

                                             = 8 * 5/2   teaspoons/cup

                                            = 20   teaspoons/cup  

So the unit rate is 20 teaspoons per cup.

Hope this explains it.