Video narration
Indha maadhiri Speed-Distance kelvigalil neelamaana equation poda aarambithaal exam time pogaamal poyvidumo endru bayamaa? Bank exam mock test-il varum indha pattern-kku shortcut idhudhaan. Equal-time enbadhaal time ondre; adhanaal distance-ai speed-aal divide seydhu equal aakkungal: (3K - 60)/20 = (1.5K + 60)/16. Cross-multiply seydhaal, 16(3K - 60) = 20(1.5K + 60); enave K = 120. Ippodhu mudhal Downstream distance 300 km. Kelviyil ketkappatta final Upstream distance, 2K + 64, adhaavadhu 304 km. 20 Downstream, 16 Upstream endru eduthaal, Still-water speed enbadhu average: 18 km/h. Stream speed, difference-in half: 2 km/h. Still-water speed-ai one-third kuraithaal, 18-il 6 kuraindhu 12. Stream speed twice aagum, adhanaal 4. Pudhiya Upstream speed: 12 - 4 = 8 km/h. Aagaave time = 304/8 = 38 hours. Exam-il mudhalil equal-time equation moolam K-ai mattum kandupidiyungal; piragu speed changes apply seyyungal. Ninaivil vaiyungal: K = 120, answer 38 hours.