1.

A fast train takes 2 hours less for a journey of 300 km in comparison to a slow train whose speed is 5 km/h less than that of the fast train. The speed of fast train is equal to

Answer»

Answer:

LET THE SPEED OF FAST TRAIN BE V

DISTANCE IS 300KM

SPEED OF SLOW TRAIN IS V_5

So

TIME TAKEN BY SLOW TRAIN IS DISTANCE/SPEED =300/(V_5)

TIME TAKEN BY FAST TRAIN =DISTANCE/SPEED =300/V

GIVEN

Time TAKEN BY FAST TRAIN IS 2 HOURS LESS THAN SLOW TRAIN

SO

300/V=300/(V_2)+2

ON CROSS MULTIPLICATION

300V_1500=290V+2V^2

10V_1500=2V^2

2V^2_10V+1500=0

V^2_5V+750=0

V^2_30V+25V=0

ON SOLVING THIS QUADRATIC EQUATION WE GET

V=30km/hr

but iam not sure of my answer



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