Jambmaths question:
y is inversely proportional to x and y = 4 when x = $\frac{1}{2}$. Find x when y =10
Option A:
2
Option B:
10
Option C:
$\frac{1}{5}$
Option D:
$\frac{1}{10}$
Jamb Maths Solution:
$\begin{align} & y\propto \frac{1}{x} \\ & y=\frac{k}{x} \\ & \text{when }x=\frac{1}{2},\text{ }y=4 \\ & 4=\frac{k}{{\scriptstyle{}^{1}\!\!\diagup\!\!{}_{2}\;}} \\ & k=4\times \frac{1}{2}=2 \\ & \text{when }y=10 \\ & 10=\frac{k}{x} \\ & x=\frac{2}{10}=\frac{1}{5} \\\end{align}$
Jamb Maths Topic:
Year of Exam: