A automobile travelling at its real speed reaches 42 kilometres in 1 hour 40 minutes and 48 seconds. Determine the car's real speed.
A. 17 6/7 km/hr
B. 25 km/hr
C. 30 km/hr
D. 35 km/hr
Answer:D
A automobile travelling at its real speed reaches 42 kilometres in 1 hour 40 minutes and 48 seconds. Determine the car's real speed.
A. 17 6/7 km/hr B. 25 km/hr C. 30 km/hr D. 35 km/hr
Explanation: 1 hr 40 min 48 sec = 1 hr 40 4/5 min = 1 51/75 hours=126/75 hours.Let's say the actual speed is x kilometres per hour.After that, 5/7 x x 126 /75= 42,42 x 7 x 75/5 x 126 = 35 km/hr x = 42 x 7 x 75/5 x 126 = 35 km/hr x = 42 x 7 x 75.