Alwyn

Alwyn spends 1 3/4 hours answering his math homework. He also spends 2 1/3 hours doing his homework in English. How much time does he spend doing his homework for these two subjects?

Correct answer:

t =  4 ¹⁄₁₂ = 49/12 h

Step-by-step explanation:

$$\begin{gathered} a=1\frac{3}{4}=1+\frac{3}{4}=\frac{1\cdot 4+3}{4}=\frac{4+3}{4}=\frac{7}{4}=1.75\text{h} \\ b=2\frac{1}{3}=2+\frac{1}{3}=\frac{2\cdot 3+1}{3}=\frac{6+1}{3}=\frac{7}{3}\doteq 2.3333\text{h} \\ t=a+b=\frac{7}{4}+\frac{7}{3}=\frac{21}{12}+\frac{28}{12}=\frac{21+28}{12}=\frac{49}{12}=\frac{49}{12}\text{h}=4\frac{1}{12}\text{h}=4.0833\text{h} \end{gathered}$$

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