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 2 of 7.
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
Vivek said:
1 decade ago
Hi @Jai
5/2*2/1=by cross multiplication
We have get 5+4/2=9/2
5/2*2/1=by cross multiplication
We have get 5+4/2=9/2
S. M. said:
1 decade ago
Simple method :- (64+84)/2 =72
Thus on safer side,
we can go with C.) 71.11 km/hr
Thus on safer side,
we can go with C.) 71.11 km/hr
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.
Fatima said:
1 decade ago
Thank you so much Sundar.
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)
Samy said:
1 decade ago
Thank you suguraman.
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........
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.
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.
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