Question

Two people started simultaneously towards eachother from A and B, which are 60 km apart. Theymet 5 hours later. After their meeting, the firstperson, who travelled from A to B, decreased hisspeed by 1.5 km/h. The other person, who travelledfrom B to A, increased his speed by 1.5 km/h. Thefirst person is known to arrive at B 2.5 hours earlierthan the second person arrived at A. Find the initialspeed of the first person.

Answer 1

Let initial speed of A be u 
initial speed of B be u'

distance covered by A in 5 hrs be d
thus distance covered by B in 5 hrs = 60 - d

Thus According to question

d/u = 60 - d/u' = 5
Thus
Solving we get
u' = 12 - u

Also
60 /u-1.5 = t - 2.5
and 
60/ u + 1.5 = t
Thus
60 (u - u') = -180 = 2.5 (u'+1.5) (u - 1.5)
Thus this way value of both u and u' can be find out

Answer 2

Answer:initially we have to use relative velocity formula as they come towards each other

They meet after 5 hrs and total distance is 60km

Let S1 and S2 be the respective speeds

So, 5=60/S1+S2

S1+S2=12

S2=12-s1

After that from problem we have given that

T1=T2-2.5 hours

T2-T1= 2.5

60/S2 - 60/S1 = 2.5 hours

So solving above equation by substituting S2= 12-s1

We get

S1= 7.22 that is approximately 7.5km/hr

Step-by-step explanation:

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