Aptitude - Time and Distance - Discussion
Discussion Forum : Time and Distance - General Questions (Q.No. 7)
7.
A man complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and second half at the rate of 24 km/hr. Find the total journey in km.
Answer: Option
Explanation:
| (1/2)x | + | (1/2)x | = 10 |
| 21 | 24 |
 |
x | + | x | = 20 |
| 21 | 24 |
15x = 168 x 20
| x = |
 |
168 x 20 |  |
= 224 km. |
| 15 |
Discussion:
141 comments Page 1 of 15.
VISHNU said:
5 days ago
Time = 10hr.
Speed = 21 and 24, 21 + 24 = 45.
Distance = speed * time.
Distance = 10*45 = 450.
The journey is 2 parts.
450/2 = 225 ~224.
Speed = 21 and 24, 21 + 24 = 45.
Distance = speed * time.
Distance = 10*45 = 450.
The journey is 2 parts.
450/2 = 225 ~224.
(2)
Nithin said:
6 months ago
The right answer is 234 km.
(3)
Ansh Raghav said:
7 months ago
@ALL.
According to the given question;
x/21 + x/24 =10
15x/168 = 10.
By cross multiplication;
168 × 10 = 15x.
1680 = 15x.
122 = x.
2x = 224.
According to the given question;
x/21 + x/24 =10
15x/168 = 10.
By cross multiplication;
168 × 10 = 15x.
1680 = 15x.
122 = x.
2x = 224.
(21)
Himanshu said:
9 months ago
Let the Distance = 2x.
So, By Formula T = D/S.
The distance covered by each = x.
10 = x/21+x/24,
5040 = 45x,
X = 122.
So Distance =2x,
= 2x122,
=224 Km.
So, By Formula T = D/S.
The distance covered by each = x.
10 = x/21+x/24,
5040 = 45x,
X = 122.
So Distance =2x,
= 2x122,
=224 Km.
(19)
Gowthaman said:
11 months ago
Let's take a formula = 2XY/X + Y.
Here, X=21 and Y= 24.
So, the formula is = 2 * 21 * 24/21 + 24,
= 1008/45.
Here, your Answer = 22.4 * 10 = 224.
Here, X=21 and Y= 24.
So, the formula is = 2 * 21 * 24/21 + 24,
= 1008/45.
Here, your Answer = 22.4 * 10 = 224.
(32)
Hardik H Bagaria said:
12 months ago
@All.
For the people who got an answer as 225km, we cannot assume that the time taken to complete half of the journey (distance) is 5hrs, assuming 5hrs for the first trip and 5 for the second is wrong.
Because its not relative to the time, but rather relative to the journey (distance).
For the people who got an answer as 225km, we cannot assume that the time taken to complete half of the journey (distance) is 5hrs, assuming 5hrs for the first trip and 5 for the second is wrong.
Because its not relative to the time, but rather relative to the journey (distance).
(48)
Pradumn said:
1 year ago
By using the formula = 2xy/x + y.
= 2 * 21 * 24/21 + 24.
= 1008/45,
= 22.4,
= 22.4 * 10.
= 224km.
= 2 * 21 * 24/21 + 24.
= 1008/45,
= 22.4,
= 22.4 * 10.
= 224km.
(33)
Francis K Joseph said:
1 year ago
Let's take a formula = 2XY/X + Y.
Here, X=21 and Y= 24.
so, the formula is = 2 * 21 * 24/21 + 24,
=1008/45.
Here, your Answer = 22.4 * 10 = 224.
Here, X=21 and Y= 24.
so, the formula is = 2 * 21 * 24/21 + 24,
=1008/45.
Here, your Answer = 22.4 * 10 = 224.
(22)
Ravinder Choudhary said:
2 years ago
X/21 + X/24 = 10,
15X/168 = 10,
X = 112,
2X = 224.
15X/168 = 10,
X = 112,
2X = 224.
(18)
AANI said:
2 years ago
Total journey = 10 hours.
Journey in 2 parts 10/2 = 5
each journey is = 5 hours.
1st journey speed =21 km/hr ;
Total of 1st journey speed = 21 x 5 =105
Total of 2nd journey speed =24 x 5 =120.
Then,
Total 1st and 2nd both journey speed = 105 + 120 = 225 km.
THANKS.
Journey in 2 parts 10/2 = 5
each journey is = 5 hours.
1st journey speed =21 km/hr ;
Total of 1st journey speed = 21 x 5 =105
Total of 2nd journey speed =24 x 5 =120.
Then,
Total 1st and 2nd both journey speed = 105 + 120 = 225 km.
THANKS.
(381)
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