From point P, at 6 : 30 pm, a train starts moving towards Q with the speed of 40 km/hr. Another train starts moving from point Q at 7:30 pm. towards point P at the speed of 60 km/hr. Both of them meet at 11:30 pm, at point R. What is the ratio of PR and QR?
Speed of first train that moves from P to Q = 40 km/hr
Now, first train started at 6:30 p.m. and reached R at 11:30 pm, thus distance travelled by it = $$PR=40\times5=200$$ km
Speed of second train that moves from Q to P = 60 km/hr
Now, distance travelled by it from 7:30 p.m. to 11:30 pm = $$PR=60\times4=240$$ km
=> $$\frac{PR}{QR}=\frac{200}{240}=5:6$$
=> Ans - (B)
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