(a)
Truth Table
[table] $p$ | $q$ | $r$ | $\sim p$ | $\sim r$ | $p \land \sim r$ | $( \sim p$
$\vee q)$ | $(p \land \sim r) \rightarrow$
$(\sim p \vee q)$ ; T
T
T
T
F
F
F
F | T
T
F
F
T
T
F
F | T
F
T
F
T
F
T
F | F
F
F
F
T
T
T
T | F
T
F
T
F
T
F
T | F
T
F
T
F
F
F
F | T
T
F
F
T
T
T
T | T
T
T
F
T
T
T
T [/table]
Hence, $(p \land \sim r) \rightarrow (\sim p \vee q)$ is F.
When $p = T,\ q = F,\ r = F$