Puppy

A family adopts a puppy that weighs seven and 7/8 pounds. Two weeks later, they take him to the vet, and he weighs 12 and 3/16 pounds. How much weight did the pit puppy gain?

Correct answer:

x =  4 ⁵⁄₁₆ = 69/16 lb

Step-by-step explanation:

$$\begin{gathered} a=7\frac{7}{8}=7+\frac{7}{8}=\frac{7\cdot 8+7}{8}=\frac{56+7}{8}=\frac{63}{8}=7.875\text{lb} \\ b=12\frac{3}{16}=12+\frac{3}{16}=\frac{12\cdot 16+3}{16}=\frac{192+3}{16}=\frac{195}{16}=12.1875\text{lb} \\ x=b-a=\frac{195}{16}-\frac{63}{8}=\frac{195}{16}-\frac{126}{16}=\frac{195-126}{16}=\frac{69}{16}=\frac{69}{16}\text{lb}=4\frac{5}{16}\text{lb}=4.3125\text{lb} \end{gathered}$$

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