Question

Complite the following table given that x varies directly as y . 

x	3	5	7	9
y	...	20	28	...

Answer 1

\[\text{ Here, x and y vary directly }  . \]
\[ \therefore x = ky\]

\[x = 5 \text{ and } y = 20\]
\[i . e . , 5 = k \times 20\]
\[ \Rightarrow k = \frac{5}{20} = \frac{1}{4}\]
\[\text{ For x = 3 and } k = \frac{1}{4}, \text{ we have:}  \]
\[3 = \frac{1}{4} \times y\]
\[ \Rightarrow y = 4 \times 3 = 12\]
\[\text{ For } x = 9, k = \frac{1}{4}, \text{ we have: }  \]
\[x = ky\]
\[ \Rightarrow 9 = \frac{1}{4} \times y\]
\[ \Rightarrow y = 9 \times 4 = 36\]