Answer
(a) $1.14atm$
(b) $321K$
Work Step by Step
(a) We can find the final pressure as follows:
$p_2=p_1(\frac{V_1}{V_2})^{\gamma}$
We plug in the known values to obtain:
$p_2=3(0.5)^{1.40}$
$\implies p_2=1.14atm$
(b) We can find the final temperature as follows:
$T_2=(\frac{V_1}{V_2})^{\gamma-1}T_1$
We plug in the known values to obtain:
$T_2=(0.5)^{1.40-1}(423)$
$\implies T_2=321K$