A solution is to be kept between 30°C and 35°C.

Let x degree Fahrenheit be the temperature of the solution.

Then, $30^{\circ} \mathrm{C}

Now, $F=\frac{9}{5} C+32$

$\Rightarrow \frac{9}{5} \times 30+32

$\Rightarrow 54+32

$\Rightarrow 86^{\circ}

Hence, the range of the temperature in Fahrenheit is between $86^{\circ}$ and $95^{\circ}$.