Two wastewater streams A and B, having an identical ultimate BOD are getting mixed to form the stream C. The temperature of the stream A is $20^{\circ}C$ and the temperature of the stream C is $10^{\circ}C$. It is given that

• the $5$-day BOD of the stream A measured at $20^{\circ}C=50$mg/I
• BOD rate constant (base $10$) at $20^{\circ}C=0.115$ per day
• temperature coefficient$=1.135$

The $5-$day BOD (in mg\I, up to one decimal place ) of the stream C, calculated at $10^{\circ} C$, is _________