Round 98,471 to the nearest ten thousands

Given:
sin(y°) = s/8
tan(y°) = s/t

note that tan(x) = sin(x)/cos(x).

therefore
sin(y°)/tan(y°) = sin(y°)*(cos(y°)/sin(y°)) =   cos(y°)

that is,
cos(y°) = (s/8)/(s/t) = (s/8)*(t/s) = t/8.

the answer choices are:
(a) 8s
(b) 8t
(c) t/8
(d) 8/t

answer: (c)
the correct answer is t/8