Are these data sets on chemical changes consistent with the law of conservation of mass?

$($a$)$ A $7\mathrm{.}5-$g sample of hydrogen gas completely reacts with $60\mathrm{.}0g$ of oxygen gas to form $67\mathrm{.}5g$ of water.

$($b$)$ A $60\mathrm{.}5-$g sample of gasoline completely reacts with $243g$ of oxygen to form $206g$ of carbon dioxide and $88g$ of water.