Question

calculate the temperature on the Celsius scale which is five times the temperature on the Fahrenheit scale

Answer 1

Suppose temperature on Fahrenheit scale is T.
Then according to question, temperature on Celsius scale will be 5T.
Now,
$$\begin{gathered} 0_{\mathrm{C}}\times \frac{9}{5}+32=0_{\mathrm{F}} \\ 5\mathrm{T}\times \frac{9}{5}+32=\mathrm{T} \\ 8\mathrm{T}=-32 \\ \mathrm{Or}\mathrm{T}=-4^0\mathrm{F} \\ \mathrm{And}5\mathrm{T}=-{20}^0\mathrm{C} \end{gathered}$$