a
(a)
We know $\frac{\Delta V}{V}=-\frac{P}{B}$
Substituting values
$\frac{-\frac{0.01}{100} \times V}{V}=\frac{-100}{B} \times 1.01 \times 10^5$ $\left\{1 \,atm =1.01 \times 10^5 \,Pa\right.$ or $\left.Nm ^{-2}\right\}$
$B=1.01 \times 10^{11} \,Nm ^{-2}$