A recipe calls for 2/3 cup of sugar for every 4 teaspoons of vanilla. How much vanilla should be used for every 1 cup?

Question

I need help figuring this out ASAP 

Answer 1

Let x = the number of teaspoons of vanilla needed

sugar/vanilla: 2/3 = 1

                           4      x           Cross multiply

(2/3)x = 4

x = 4(3/2)

x = 6 teaspoons