Answer
$6.6\times 10^8Pa$
Work Step by Step
We can find the required pressure as follows:
$\Delta V=90.5\%=0.0905$
$V_{\circ}=1+0.0905=1.0905$
and the fractional change in volume is given as
$\frac{\Delta V}{V_{\circ}}=\frac{-0.0905}{1.0905}=-0.083$
Now $\Delta P=-B(\frac{\Delta V}{V_{\circ}})$
We plug in the known values to obtain:
$\Delta P=(-0.8\times 10^{10^{10}N/m^2})(-0.083)$
$\Delta P=6.64\times 10^8Pa$
The required pressure is
$P_f=P_i+\Delta P$
We plug in the known values to obtain:
$P_f=1.01\times 10^5Pa+6.64\times 10^8Pa$
$P=6.6\times 10^8Pa$