Ronit and Sonali is 50 km apart. When they move in opposite direction they meet in 5 hours. If Ronit moves at \(\frac{3}{4}\)th of his speed and Sonali at 1/4th of her speed then they meet in 8 hours 20 min . Find the speed of Ronit .
Answer & explanation
Correct answer: option 3
Distance = Speed × Time
Distance = 50 km
Time = 5 hours
Speed = \(\frac{50}{5}\) = 10 km/hr
Speed of ( ronit + sonali ) = 10 km/hr
R + S = 10 km/hr ------------ ( 1 )
Ronit moves at 3/4th of his speed and Sonali at 1/4th of her speed then they meet in 8 hours 20 min .
8 hours 20 min = 8 + \(\frac{1}{3}\) = \(\frac{25}{3}\) hours
Speed = \(\frac{50 × 3}{25}\) = 6 km/hr
\(\frac{3}{4}\)R + \(\frac{1}{4}\)S = 6 km/hr
3R + 1R = 24 km/hr ---------- ( 2 )
subtract equation ( 2 ) from ( 1 )
2R = 14 km/hr
1R = 7 km/hr
Speed of Ronit = 7 km/hr