## Elementary Technical Mathematics

$$3 \ h\ 52\ min \ 30 s$$
Since 1 h=60 min and 1 min =60 s, then we have $$13,950 \ s =\frac{19,350}{60*60}\ h=3.875 \ h= 3 \ h\ 52.5\ min \\ = 3 \ h\ 52\ min \ 30 s.$$