Radha and shyam start travelling from delhi to goa at a speed of 15km/h and 12km/h respectively. After half an hour meera also leaves from delhi to goa. After some time meera crosses shyam and 90 minutes further on meera crosses radha. Find the speed of meera
Answers
Answer:
speed of Meera is 47 km/hour.
Step-by-step explanation:
Let Meera speed is x km/s.
Let Meera meet Shyam at t hours.
At the time of meeting, distance traveled by both are same.
Distance traveled by Shyam = Distance traveled by Meera
from Distance = speed x time, we can derive.
(Speed of Shyam = 12 km/h)
12t = x(t - 0.5) (Since Meera started half an hour late)
2(12 - x)t + x = 0
t = x/2(x - 12) ---------------E1
After 90 minutes, Meera and Radha met.
Distance traveled by Radha = Distance traveled by Meera
15(t + 3/2) = x(t + 3/2 - 0.5)
15(t + 3/2) = x (t + 1)
15(2t + 3) = 2x(t + 1)
30t + 45 = 2xt + 2
-43 = (30 - 2x)t
t = 43 / (2x - 30) -----------E2.
Equating E1 and E2, we get
x/(2(x - 12) = 43 / (2x - 30)
x(2x - 30) = 86(x - 12)
2x² -116x + 1032 = 0
x² - 58x + 516 = 0
Solving x we get x = 47.0 and 10.9.
Since speed of Meera can not be less than other two. We ignore 10.9.
Hence speed of Meera is 47 km/hour.
Answer:
Step-by-step explanation:
