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Question
Complite the following table given that x varies directly as y .
| x | 2.5 | ... | ... | 15 |
| y | 5 | 8 | 12 | ... |
Solution
\[\text{ Here, x and y vary directly } . \]
\[ \therefore x = ky\]
\[x = 2 . 5 \text{ and } my = 5\]
\[i . e . , 2 . 5 = k \times 5\]
\[ \Rightarrow k = \frac{2 . 5}{5} = 0 . 5\]
\[\text{ For y = 8 and k = 0 . 5, we have } : \]
\[x = ky\]
\[ \Rightarrow x = 8 \times 0 . 5 = 4\]
\[\text{ For y = 12 and k = 0 . 5, we have: } \]
\[x = ky\]
\[ \Rightarrow x = 12 \times 0 . 5 = 6\]
\[\text{ For x = 15 and k = 0 . 5, we have } : \]
\[x = ky\]
\[ \Rightarrow 15 = 0 . 5 \times y\]
\[ \Rightarrow y = \frac{15}{0 . 5} = 30\]
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