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 3 of 7.
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.
Vijayalakshmi V said:
5 years ago
The average speed = 2xy/(x+y).
where x=64 kmph y = 80 kmph,
Therefore, 2(64)(80)/(64+80) = (8)(80)/9.
= 640/9.
= 71.11 kmph.
where x=64 kmph y = 80 kmph,
Therefore, 2(64)(80)/(64+80) = (8)(80)/9.
= 640/9.
= 71.11 kmph.
(1)
Prveen Bilimoga said:
1 decade ago
I have a doubt, can we do like this, the first 160 hrs is 64 km speed, and the second hr is 80, total 144. so 144/2 = to 72
Pronoi said:
7 years ago
Average speed =2 * 64 * 80/64+80.
= 10240/144.
= 71.11 km/hr.
= 10240/144.
= 71.11 km/hr.
Prajweetha said:
1 decade ago
Hello jai,
By simplyfying 160/64 we will get 5/2, while 160/80 becomes 2/1
By taking 2 as LCM we will get 5+4/2=9/2
By simplyfying 160/64 we will get 5/2, while 160/80 becomes 2/1
By taking 2 as LCM we will get 5+4/2=9/2
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.
Haseeb said:
2 years ago
Total distançe = 160+160=320
Total time = 160/64+160/80 = 4.5 = 9/2.
Av speed = TD/TT.
= 320/9/2.
= 71.11km/h.
Total time = 160/64+160/80 = 4.5 = 9/2.
Av speed = TD/TT.
= 320/9/2.
= 71.11km/h.
(23)
Kunal Savle said:
3 years ago
We can use,
Avg= 64 + 80/2.
= 144/2.
= 72 kmph.
= 72
So, here the answer is 71.11 kmph.
Avg= 64 + 80/2.
= 144/2.
= 72 kmph.
= 72
So, here the answer is 71.11 kmph.
(46)
Ajay said:
8 years ago
Total speed 320km/hr.
64km/h + 80km/hr= 144km/hr.
So the average speed is 144/2= 72 km/hr.
64km/h + 80km/hr= 144km/hr.
So the average speed is 144/2= 72 km/hr.
Nisha said:
2 decades ago
Can we use the formula for avg speed, ie: 2xy/(x+y) ?This formula gives a different answer.
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