**Time and Distance- Key Notes**

**Time and Distance- Key
Notes-aptitude-questions-answers-basics**

**Time, Speed and
Distance Aptitude basics, practice questions, answers and
explanations **

**Prepare for companies tests and interviews**

Distance= Speed*time

For a non-uniform motion Average speed= Total distance travelled/Total time
taken

When the body travels at 'u' m/s for t1 seconds and 'v' m/s for t2 seconds,
then

Average speed= (ut1+vt2)/(t1+t2)

When the body travels l distance at 'u' m/s and 'm' distance at 'v' m/s;
Average speed = (mu+lv)/(l+m)

**Relative Speed:** Speed of a
moving body w.r.t. another moving body is called relative speed.

Speed of A w.r.t. B

(i) When they are moving in same
direction; Relative speed of A= A-B

(ii) When they are moving in opposite
direction; Relative speed of A= A+B

**Key points on Trains**

When a train is crossing a pole distance
travelled by the train= length of train

When a train of length l is crossing a
bridge of length b; the distance travelled by train=l+b

When a train of length l is crossing a
platform of length p; then distance travelled by train=l+p

When a train of length l1 is crossing/
overtaking another train l2; then distance travelled = l1+l2

**Exercise questions**

1. Train A traveling at 60 km/hr leaves
Mumbai for Delhi at 6 P.M. Train B traveling at 90 km/hr also leaves Mumbai for
Delhi at 9 P.M. Train C leaves Delhi for Mumbai at 9 P.M. If all three trains
meet at the same time between Mumbai and Delhi, what is the speed of Train C if
the distance between Delhi and Mumbai is 1260 kms?

A) 60
km/hr

B) 90 km/hr

C) 120 km/hr

D) 135 km/hr

2. Two trains A and B start
simultaneously from stations X and Y towards each other respectively. After
meeting at a point between X and Y, train A reaches station Y in 9 hours and
train B reaches station X in 4 hours from the time they have met each other. If
the speed of train A is 36 km/hr, what is the speed of train B?

A) 24 km/hr

B) 54 km/hr

C) 81 km/hr

D) 16 km/hr

3. A man moves from A to B at the rate
of 4 km/hr. Had he moved at the rate of 3.67 km/hr, he would have taken 3 hours
more to reach the destination. What is the distance between A and B?

A) 33 kms

B) 132 kms

C) 36 kms

D) 144 kms

4. A man driving his bike at 24 kmph
reaches his office 5 minutes late. Had he driven 25% faster on an average he
would have reached 4 minutes earlier than the scheduled time. How far is his
office?

A) 24 km

B) 72 km

C) 18 km

D) Data Insufficient

5. A man and a woman 81 miles apart from
each other, start traveling towards each other at the same time. If the man
covers 5 miles per hour to the women's 4 miles per hour, how far will the woman
have travelled when they meet?

A)
27

B)
36

C)
45

D) None of these.

6. The speed of a motorboat itself is 20
km/h and the rate of flow of the river is 4 km/h. Moving with the stream the
boat went 120 km. What distance will the boat cover during the same time going
against the stream?

A) 80
km

B) 180
km

C) 60 km

D) 100 km

7. I travel the first part of my journey
at 40 kmph and the second part at 60 kmph and cover the total distance of 240
km to my destination in 5 hours. How long did the first part of my journey
last?

A) 4 hours B) 2 hours C) 3 hours D) 2
hours 24 minutes

8. By walking at 3/4th of his usual
speed, a man reaches office 20 minutes later than usual. What is his usual
time?

A) 30 min

B) 60 min

C) 70 min

D)50 min

9. A passenger train covers the distance
between stations X and Y, 50 minutes faster than a goods train. Find this distance
if the average speed of the passenger train is 60 kmph and that of goods train
is 20 kmph.

A) 20 kms

B) 25 kms

C) 45 kms

D) 40 kms

10. Ram covers a part of the journey at
20 kmph and the balance at 70 kmph taking total of 8 hours to cover the
distance of 400 km. How many hours has been driving at 20 kmph?

A) 2 hours

B) 3 hours 20 minutes

C) hours 40 minutes

D)3 hours 12 minutes

**Answer Key**

1.C; 2.B; 3.B; 4.C; 5.B; 6.A; 7.C; 8.B;
9.B; 10.D