Solution:
Solution
The husband tells lie in $$30\% = 0.3$$ cases.
The wife tells lie in $$35\% = 0.35$$ cases.
The probability that they
both will contradict is,
$$P = P\left(
{{\rm{husband}}\;{\rm{lies}}\;{\rm{but}}\;{\rm{wife}}\;{\rm{don't}}} \right) +
P\left( {{\rm{wife}}\;{\rm{lies}}\;{\rm{but}}\;{\rm{husband}}\;{\rm{don't}}}
\right)$$
$$ = 0.3\left( {1 - 0.35}
\right) + \left( {0.35} \right)\left( {1 - 0.3} \right)$$
$$ = 0.195 + 0.245$$
$$ = 0.44$$
$$ = 44\% $$