Gopal travels from A to B at the speed of 5km/h, from B to C at 10 km/h, and from C to D at 15 km/h. If AB = BC = CD, then find Gopal’s average speed.
Answer & explanation
Correct answer: option 1
According to question ,
AB = BC = CA
LCM of ( 5 , 10 , 15 ) = 30
Let Distance = 30 km
Total distance = 30 + 30 + 30 = 120 km
Time AB = \(\frac{30}{5}\) = 6 hours
Time BC = \(\frac{30}{10}\) = 3 hours
Time CA = \(\frac{30}{15}\) = 2 hours
Average speed = \(\frac{Total \; Distance }{Total \; Time }\)
= \(\frac{90}{11}\)
= 8\(\frac{2}{11}\) km/h