LA5 marksYear: 2025MediumCBSE Class 10
quadratic-equationsspeed-distance-timeword-problems
Question
The time taken by a person to travel an upward distance of 150 km was 221 hours more than the time taken in the downward return journey. If he returned at a speed of 10 km/h more than the speed while going up, find the speeds in each direction.
Solution
1
Let the speed in upward direction be x km/h and the speed in downward direction =(x+10) km/h.
ATQ:
+1 mark2
x150−x+10150=25
⇒x2+10x−600=0
+2 marks3
⇒(x+30)(x−20)=0
+0.5 marks4
∴x=20 (rejecting x=−30)
and x+10=20+10=30
+0.5 marks5
Therefore, speeds in upward and downward direction are 20 km/h and 30 km/h respectively.
+1 mark