A train takes 2½ hours less for a journey of 300 km, if its speed is increased by 20 km/h from its usualspeed. How much time will it take to cover a distance of 192 km at its usual speed? a) 6 hoursb) 4.8 hoursc) 3 hoursd) 2.4 hours About the author Arianna
Answer: 4.8hours Step-by-step explanation: Let X be the usual speed 300/x – 300/x+20=5/2 Taking lcm to be x(x+20) then: X²+20x-2400(in the simplified form) The roots of the quadratic equation are: X=40 or x=-60(disqualified) So 40 is the usual speed. Time=distance/speed =192km/40km/hr =4.8hours =4.8 hours Reply
Answer:
4.8hours
Step-by-step explanation:
Let X be the usual speed
300/x – 300/x+20=5/2
Taking lcm to be x(x+20) then:
X²+20x-2400(in the simplified form)
The roots of the quadratic equation are:
X=40 or x=-60(disqualified)
So 40 is the usual speed.
Time=distance/speed
=192km/40km/hr
=4.8hours
=4.8 hours