Two trains of equal length 120 metres move in the same direction

Two trains of equal length 120 metres move in the same direction. The faster train completely overtakes the slower one in 15 seconds. If the slower train were to move at half its speed, the over taking would take in 10 seconds. At what speeds are the 2 trains moving ?

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #74469