the time taken by a person to cover 150 km was 2 1/2 hour more than time taken in the return journey.if he returned at a speed of 10 km/h morethan the speed while going.find the speed per hour in each direction?
Answers
Step-by-step explanation:
⇒ Distance given =150km
⇒ Let the forward speed be x and the return speed will be x+10
We know that, Time=speedDistance
∴ x150=x+10150+2.5
⇒ 150(x+10)−150x=2.5×x(x+10)
⇒ 150x+1500−150x=2.5x2+25x
⇒ 2.5x2+25x−1500=0
⇒ 25x2+250x−15000=0
⇒ x2+10x−600=0
⇒ x2+30x−20x−600=0
⇒ x(x+30)−20(x+30)=0
⇒ (x+30)(x−20)=0
The value of cannot be negative.
∴ Forward speed will be 20km/hr
Answer:
Forward speed = 20 Kmph
Return Speed = 30 Kmph
Step-by-step explanation:
D = 150km.
Let the forward speed be S
The return speed will be S + 10.
We know that time = distance/speed
150/S - 150/(S+10) =2.5
150 (S + 10) - 150S = 2.5 x ( S + 10 )(S)
S² + 10S - 600 = 0
(S+30) (S-20) = 0
S = -30 and S = 20. Speed cannot be negative S = 20 Kmph
Forward speed = S = 20 Kmph
Return Speed = S + 10 = 30 Kmph