What is the period of f(t)=sin( t / 30 )+ cos( (t)/ 4) ?

$120 \pi$
Period of sin (t/30) --> $30 \left(2 \pi\right) = 60 \pi$
Least common multiple of $60 \pi \mathmr{and} 8 \pi$ is --> $120 \pi$
Period of f(t) --> $120 \pi$