100+ Problems on Time and Distance with Solutions Pdf - 8

 Question: 6

A car covers the first 39 kms of its journey in 45 minutes and covers the remaining 25 km in 35 minutes. What is the average speed of the car?

(A) 48 km/hr

(B) 58 km/hr

(C) 64 km/hr

(D) 68 km/hr

View Answer

Ans: A

Total distance travelled = (39 + 25)km = 64 km.

Total time taken = (45 + 35) min = 80 min = 

4

3

 hr.

∴ Average speed = (64×

3

4

)km/hr = 48 km/hr.

Question: 7

Three persons are walking from a place A to place B. Their speeds are in the ratio of 4 : 3 : 5. The time ratio to reach B by these persons will be

(A) 4 : 3: 5

(B) 15 : 9 : 20

(C) 15 : 20 : 12

(D) 15 : 22 : 02

View Answer

Ans: C

Ratio of speeds = 4 : 3 : 5

∴ Ratio of times taken = 

1

4

 : 

1

3

 : 

1

5

 = 15 : 20 : 12.

Question: 8

A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.?

(A) 4

(B) 5

(C) 6

(D) 7

View Answer

Ans: D

Relative speed = (2 + 3) = 5 rounds per hour.

So, they cross each other 5 times in an hour and 2 times in half an hour.

Hence, they cross each other 7 times before 9.30 a.m.

Question: 9

If a man running at 15 km/hr crosses a bridge in 5 minutes, then the length of the bridge is

(A) 1000 m

(B) 1250 m

(C) 7500 m

(D) 9000 m

View Answer

Ans: B

Speed = (15×

5

18

) m/sec = 

25

6

 m/sec

Distance covered in 5 min = (

25

6

×5×60) m = 1250 m.

Question: 10

A train running at 

7

11

 of its own speed reached a place in 22 hours. How much time could be saved if the train would have run at its own speed?

(A) 6 hours

(B) 7 hours

(C) 8 hours

(D) 14 hours

View Answer

Ans: C

New speed = 

7

11

 of usual speed.

∴ New time = 

11

7

 of usual time.

So, 

11

7

 of usual time = 22 hrs.

⇔ usual time = (

22×7

11

) = 14 hrs.

Hence time saved = (22 - 14) = 8 hrs.