IF A BROWNIE RECIPE IS FOR 12 SERVINGS AND USES 1/2 CUP OF NUTS IF IT IS REDUCED TO 10 SERVINGS HOW MANY CUPS OF NUTS ARE NEEDED

Question

I am not sure what formula to use.

Answer 1

Set up a proportion. ¹² / _1/2 = ¹⁰ / _x. Cross multiply 12 and x = 12x. Then cross multiply 10 and 1/2 = 5. So you have 12x = 5. Divide both sides by 12, giving you x = 0.4167. The 6 actually repeats, so I rounded it to a 7. The answer can also be written as a fraction of      ⁵ / ₁₂. 

Answer 2

You could use a proportion: (1/2) /12 = x/10

1/2/12 = 1/2*1/12 = 1/24

 

So 1/24 = x/10  If you cross-multiply, you get: 10 = 24x, so dividing by 24 gives x = 10/24, which reduces to 5/12 of a cup.