Aptitude - Time and Distance - Discussion
Discussion Forum : Time and Distance - General Questions (Q.No. 9)
9.
A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is:
Answer: Option
Explanation:
| Total time taken = |  |
160 | + | 160 |  hrs. |
= | 9 | hrs. |
| 64 | 80 | 2 |
 Average speed = |
|
320 x | 2 | km/hr |
= 71.11 km/hr. |
| 9 |
Discussion:
63 comments Page 5 of 7.
Sajnan said:
1 decade ago
This is simple:
First calculate 160/64 = 2.5.
Then 160/60 = 2.
=>2.5+2 = 4.5.
Then calculate 320/4.5 = 71.11.
First calculate 160/64 = 2.5.
Then 160/60 = 2.
=>2.5+2 = 4.5.
Then calculate 320/4.5 = 71.11.
Javid Mir said:
1 decade ago
Simple;
Average speed = 2xV1xV2/V1+V2.
Avg. Speed = 2x64x80/64+80.
Avg. Speed = 2x64x80/144.
Solving we get; avg speed = 71.1 Km/hr.
Average speed = 2xV1xV2/V1+V2.
Avg. Speed = 2x64x80/64+80.
Avg. Speed = 2x64x80/144.
Solving we get; avg speed = 71.1 Km/hr.
Jeevan said:
1 decade ago
We have to use like this also,
Total distance = 320.
1st half = 160.
2nd half = 160.
1st half speed = 64km/hr.
2nd half speed = 80km/hr.
Avg speed of 320km(dist) = 2*(64*80)/64+80 = 71.11 km/hr.
Total distance = 320.
1st half = 160.
2nd half = 160.
1st half speed = 64km/hr.
2nd half speed = 80km/hr.
Avg speed of 320km(dist) = 2*(64*80)/64+80 = 71.11 km/hr.
Siva said:
1 decade ago
Speed=distance/time.
A) first time: 160/64 = 2.5.
B) second time: 160/80 = 2.
a+b = 2. 5+2 = 4.5.
Average speed=320/4.5 = 71.11.
A) first time: 160/64 = 2.5.
B) second time: 160/80 = 2.
a+b = 2. 5+2 = 4.5.
Average speed=320/4.5 = 71.11.
Samiksha said:
1 decade ago
Simply you can aplly the formula ie,
2ab/a+b
then, you will get your answer.
2ab/a+b
then, you will get your answer.
Anshu said:
1 decade ago
Time = distance speed^-1
time = 160 / 64 = 10 / 4 = 2.5 hour
time taken for the second half = 160 / 80 = 2 hour
total time taken = 4.5 hour
total distance = 160 + 160 = 320
speed = distance time^-1
speed = 320 / 4.5 = 3200/ 45 = 355.5555.../5 = 71.1111........
time = 160 / 64 = 10 / 4 = 2.5 hour
time taken for the second half = 160 / 80 = 2 hour
total time taken = 4.5 hour
total distance = 160 + 160 = 320
speed = distance time^-1
speed = 320 / 4.5 = 3200/ 45 = 355.5555.../5 = 71.1111........
Samy said:
1 decade ago
Thank you suguraman.
Shro said:
1 decade ago
Guys,Why ru making it so comlicated...its simple speed=distance by time formula.
then distance is 320 and time is 9/2.
So speed=(320)/(9/2)
which is as per simple calculation
it can also be written as:
320*(2/9)
then distance is 320 and time is 9/2.
So speed=(320)/(9/2)
which is as per simple calculation
it can also be written as:
320*(2/9)
Fatima said:
1 decade ago
Thank you so much Sundar.
Sugumaran said:
1 decade ago
Hai praveen and S. M.
Your method is not suitable for all cases. Please avoid this method for solving this type of questions.
Your method is not suitable for all cases. Please avoid this method for solving this type of questions.
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