A confined aquifer of $15 \: m$ constant thickness is sandwiched between two aquicludes as shown in the figure (not drawn to scale).

The heads indicated by two piezometers P and Q are $55.2 \: m$ and $34.1 \: m$, respectively. The aquifer has a hydraulic conductivity of $80 \: m/day$ and its effective porosity is $0.25$. If the distance between the piezometers is $2500 \: m$, the time taken by the water to travel through the aquifer from piezometer location P to Q (in days, round off to $1$ decimal place) is ______