if a cyclist had gone 3km/hr faster he would have taken ihour 20 minutes less to ride 8km. What time did he take?
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From the question,
Let the initial speed be x
Then we know that time= distance/speed
Here let x be in hour and distance in km.
So, for the first case, let us assume that time, t1= 80/x
for the second case, then time,t2= 80/(x+3)
So now the equation will be,
(80/x)-(80/(x+3))= 1h 20 m or 4/3h
solving this we get a linear equation, i.e, x^2-3x-180=0
Solving this we get x= 12 or -15.
So our ans is 12 km/h initially. and later on 15 km/h.
So, t1= 80/12= 6.67 h
and t2= 80/15= 5.33 h
Let the initial speed be x
Then we know that time= distance/speed
Here let x be in hour and distance in km.
So, for the first case, let us assume that time, t1= 80/x
for the second case, then time,t2= 80/(x+3)
So now the equation will be,
(80/x)-(80/(x+3))= 1h 20 m or 4/3h
solving this we get a linear equation, i.e, x^2-3x-180=0
Solving this we get x= 12 or -15.
So our ans is 12 km/h initially. and later on 15 km/h.
So, t1= 80/12= 6.67 h
and t2= 80/15= 5.33 h
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