Acertain recipe calls for 2/3 cup of flour. a chef is making an amount that is 3/7 of the recipe . how much should flour should the chef use?

2/7 cup of flour

Simply multiply 2/3 by 3/7 to get the answer. To multiply 2 fractions together, you multiply the numerators together and then multiply the denominator together.

2/3 x 3/7 = 6/21

But 6/21 can be expressed in a simpler fashion. Notice that both 6 and 21 can be evenly divided by 3. So divide both the numerator and denominator by 3

(6/3)/(21/3) = (2)/(7) = 2/7