Mathematics

Problem

\triangle PQR

, points

S

and

T

lie on

PQ

and

PR

respectively such that

ST \parallel QR

. Which one of the following equalities is always true? a)

\dfrac{PS}{SQ}=\dfrac{PR}{RQ}

\dfrac{SQ}{PS}=\dfrac{PT}{TR}

\dfrac{PS}{SQ}=\dfrac{PT}{TR}

\dfrac{PS}{PT}=\dfrac{SQ}{PR}