The closest you can get to a 2/3rds decimal is 0.66 and that goes to infinity.
It is a never ending decimal.
Answer: 
Step-by-step explanation:
The measure of the third unknown arc is
.
So, 
The ration is 10/7
Divide 55 and 35 by 5 to reduce the fraction of 55/35 and you get 10/7
The answer is <span>She went over by one over six of a cup
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<span>1 cup of that particular chocolate powder has a mass of 128 grams: 1c = 128g
</span><span>64 grams of chocolate powder is x cups.
1c = 128g
x = 64g
1c : 128 g = x : 64g
x = </span>1c : 128 g * 64 g
x = 0.5 c
64 grams of chocolate powder is 0.5 cups = 1/2 cups
<span>She added two over three of a cup of chocolate powder: 2/3 cups
She need to add 1/2 cups: 1/2 = 3/6 cups
She added 2/3 cups: 2/3 = 4/6 cups
So she added 4/6 - 3/6 = 1/6 cups more.
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