Three friends

Chad and his two friends are picking blueberries at a local farm. Chad picked 2 1/2 pounds of blueberries, and one of his friends picked 1 3/8 pounds. If they ended up with a total of 5 1/4 pounds, how many pounds did Chad's other friend pick? Express your answer as a mixed number.

Correct answer:

c =  1 ³⁄₈ = 11/8 lb

Step-by-step explanation:

$$\begin{gathered} a=2\frac{1}{2}=2+\frac{1}{2}=\frac{2\cdot 2+1}{2}=\frac{4+1}{2}=\frac{5}{2}=2.5\text{lb} \\ b=1\frac{3}{8}=1+\frac{3}{8}=\frac{1\cdot 8+3}{8}=\frac{8+3}{8}=\frac{11}{8}=1.375\text{lb} \\ t=5\frac{1}{4}=5+\frac{1}{4}=\frac{5\cdot 4+1}{4}=\frac{20+1}{4}=\frac{21}{4}=5.25\text{lb} \\ a+b+c=t \\ c=t-a-b=\frac{21}{4}-\frac{5}{2}-\frac{11}{8}=\frac{42}{8}-\frac{20}{8}-\frac{11}{8}=\frac{42-20-11}{8}=\frac{11}{8}=\frac{11}{8}\text{lb}=1\frac{3}{8}\text{lb}=1.375\text{lb} \end{gathered}$$

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