Stephan - cookies

Stephan is making cookies for the class. He has a recipe that calls for 3 and 1/2 cups of flour. He has 7/8 a cup of wheat flour and 2 and 1/2 cups white flour. Does Mr. Stephan have enough flour to make the cookies?

Result

x=

Yes

No

Step-by-step explanation:

$$\begin{gathered} r=3\frac{1}{2}=3+\frac{1}{2}=\frac{3\cdot 2+1}{2}=\frac{6+1}{2}=\frac{7}{2}=3\frac{1}{2}=3.5\text{cup} \\ a=\frac{7}{8}=0.875\text{cup} \\ b=2\frac{1}{2}=2+\frac{1}{2}=\frac{2\cdot 2+1}{2}=\frac{4+1}{2}=\frac{5}{2}=2\frac{1}{2}=2.5\text{cup} \\ s=a+b=\frac{7}{8}+\frac{5}{2}=\frac{7}{8}+\frac{20}{8}=\frac{7+20}{8}=\frac{27}{8}=3\frac{3}{8}=3.375\text{cup} \\ s<r \\ x=0 \end{gathered}$$

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