2
Q:

# A man covered a certain distance at some speed. Had he moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. The distance (in km) is

 A) 30 B) 36 C) 40 D) 42

Explanation:

Let distance = x km and usual rate = y kmph.
Then, x/y - x/(y+3) = 40/60 --> 2y (y+3) = 9x ----- (i)
Also, x/(y-2) - x/y = 40/60 --> y(y-2) = 3x -------- (ii)
On dividing (i) by (ii), we get:

x = 40 km.

Q:

Kamal consistently runs 240 meters a day and on Saturday he runs for 400 meters. How many kilometers will he have to run in four weeks ?

 A) 5.75 kms B) 7.36 kms C) 8.2 kms D) 6.98 kms

Explanation:

Total running distance in four weeks = (24 x 240) + (4 x 400)

= 5760 + 1600

= 7360 meters

= 7360/1000

=> 7.36 kms

2 38
Q:

K and L starts walking towards each other at 4 pm at speed of 3 km/hr and 4 km/hr respectively. They were initially 17.5 km apart. At what time do they meet ?

 A) 6:00 am B) 6:30 pm C) 5:45 am D) 5:52 pm

Explanation:

Suppose they meet after 'h' hours

Then

3h + 4h = 17.5

7h = 17.5

h = 2.5 hours

So they meet at => 4 + 2.5 = 6:30 pm

9 174
Q:

P, Q and R start simultaneously from A to B. P reaches B, turns back and meet Q at a distance of 11 km from B. Q reached B, turns back and meet R at a distance of 9 km from B. If the ratio of the speeds of P and R is 3:2, what is the distance between A and B ?

 A) 99 B) 100 C) 89 D) 1

Explanation:

Let, Distance between A and B = d

Distance travelled by P while it meets Q = d + 11

Distance travelled by Q while it meets P = d – 11

Distance travelled by Q while it meets R = d + 9

Distance travelled by R while it meets Q = d – 9

Here the ratio of speeds of P & Q => SP : SQ = d + 11 : d – 11

The ratio of speeds of Q & R => SQ : SR = d + 9 : d – 9

But given Ratio of speeds of P & R => P : R = 3 : 2

$\inline \fn_jvn \frac{SP}{SR} = \frac{SP}{SQ}x\frac{SQ}{SR} = \frac{(d+11)(d+9)}{(d-11)(d-9)}$

=> $\inline \fn_jvn \frac{(d+11)(d+9)}{(d-11)(d-9)}=\frac{3}{2}$

=>  d = 1, 99

=> d = 99 satisfies.

Therefore, Distance between A and B = 99

6 98
Q:

A man can row 8 kmh in still water. If the river is running at 2 kmh, it takes 4 hrs more upstream than to go downstream for the same distance. Then the distance is given by

 A) 54 kms B) 32 kms C) 45 kms D) 60 kms

Explanation:

Let the distance be d.

$\inline \fn_jvn \frac{d}{8-2}-\frac{d}{8+2}=4$

=> 2d = 120

=> d = 60 kms.

5 337
Q:

In what time a 360 m. long train moving at the speed of 44 km/hr will cross a 140 m. long bridge ?

 A) 36 sec B) 39 sec C) 41 sec D) 43 sec

Explanation:

Speed = 44 kmph x 5/18 = 110/9 m/s

We know that, Time = distance/speed

Time = (360 + 140) / (110/9)

= 500 x 9/110 = 41 sec.