Aptitude - Time and Distance - Discussion

Discussion Forum : Time and Distance - General Questions (Q.No. 11)
11.
In covering a distance of 30 km, Abhay takes 2 hours more than Sameer. If Abhay doubles his speed, then he would take 1 hour less than Sameer. Abhay's speed is:
5 kmph
6 kmph
6.25 kmph
7.5 kmph
Answer: Option
Explanation:

Let Abhay's speed be x km/hr.

Then, 30 - 30 = 3
x 2x

6x = 30

x = 5 km/hr.

Discussion:
209 comments Page 11 of 21.

Shah jay said:   1 decade ago
Then what is the speed of Sameer?

Asim said:   1 decade ago
If suppose x speed abay cover in y+2 time.

Then 2x speed he covered in y-1. (here why is sameer to cover time).

Then different between time = (y+2) - (y-1) =3. So.

First covered time - second covered time = 3.

Distance = 30.

Abhay's normal speed = x.
Abhay doubles speed = 2x.
Sameer's time = t.

t+2 = 2 hrs + sameer's time.

t-1 = 1 hr less than sameer's time.

[30/x] - [30/2x] = [t+2] - [t-1].
[30/x] - [30/2x] = 3.

[1/x] - [1/2x] = 1/10.
(2-1) /2x = 1/10.

1/2x = 1/10.
2x = 10.

x = 5 km/hr.

Ani said:   1 decade ago
Can any one use proper formula of maths to solve this question because it is all confusing?

SWATHI said:   10 years ago
Please explanation clearly.

Karim Mirazul said:   10 years ago
Hey just stick with anyone solution then you will definitely sure about the solution, don't go for each and every solution. Because it will confuse you. And yes nice explanation by @Devi :).

Sahil said:   10 years ago
How 3 comes?

Sanjay parashar said:   10 years ago
Guys please solve this question by answer don't get confused.

Example: 1st option is 5 km/hr if we take then Abhaya speed 30/5 = 6 hr then Sameer has time 4 hr means Abay has 2 hr more then Sameer after then speed double means 10 km/hr, Abhay takes time 30/10 = 3 hr mean 1 hr less then Sameer. So 1st option is correct answer.

Anand said:   10 years ago
We know that:

D = ST.

Case 1 : Let's x be the time taken by Sameer.

So, 30 = s(x+2) ----- 1.

Case 2: If Abhay doubles the speed, 1 hr less than Sameer.

So 30 = 2s(x-1) ----- 2.

Equate 1 and 2.

We can get x+2 = 2x-1.

x = 4.

Put x = 4 in any of the equation.

So we will get s = 5 km/hr.

Keshav said:   10 years ago
Please I'm not getting how that 3 came please explain anyone?

Mayank said:   9 years ago
Please, anyone explain from where 3 came?


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