Verbal Reasoning - Arithmetic Reasoning - Discussion
Discussion Forum : Arithmetic Reasoning - Section 2 (Q.No. 2)
2.
David gets on the elevator at the 11th floor of a building and rides up at the rate of 57 floors per minute. At the same time, Albert gets on an elevator at the 51st floor of the same building and rides down at the rate of 63 floors per minute. If they continue travelling at these rates, then at which floor will their paths cross ?
Answer: Option
Explanation:
Discussion:
12 comments Page 1 of 2.
Swaroop said:
10 years ago
Let they meet after x minutes.
Distance = Speed*Time.
11+57x = 51-63x.
57x+63x = 51-11.
120x = 40.
x = 40/120.
x = 1/3.
Albert will cover 1/3*63 = 21 floor from 51st floor.
51-21 = 30th floor.
David will cover 1/3*57 = 19 floor from 11th floor.
11+19 = 30th floor.
Distance = Speed*Time.
11+57x = 51-63x.
57x+63x = 51-11.
120x = 40.
x = 40/120.
x = 1/3.
Albert will cover 1/3*63 = 21 floor from 51st floor.
51-21 = 30th floor.
David will cover 1/3*57 = 19 floor from 11th floor.
11+19 = 30th floor.
Monika Gupta said:
1 decade ago
Let us assume they meet after x minutes.
Distance = speed * Time .
11+57x = 51-63x.
x = 1/3.
Albert will cover 1/3*63 = 21 floor from 51st floor.
51-21 = 30th floor.
David will cover 1/3*57 = 19 floor from 11th floor.
11+19 = 30th floor.
Distance = speed * Time .
11+57x = 51-63x.
x = 1/3.
Albert will cover 1/3*63 = 21 floor from 51st floor.
51-21 = 30th floor.
David will cover 1/3*57 = 19 floor from 11th floor.
11+19 = 30th floor.
Ahmad said:
8 years ago
Let us assume they meet after x minutes.
Distance = speed * Time .
11+57x = 51-63x.
x = 1/3.
Albert will cover 1/3*63 = 21 floor from 51st floor.
51-21 = 30th floor.
David will cover 1/3*57 = 19 floor from 11th floor.
11+19 = 30th floor.
Distance = speed * Time .
11+57x = 51-63x.
x = 1/3.
Albert will cover 1/3*63 = 21 floor from 51st floor.
51-21 = 30th floor.
David will cover 1/3*57 = 19 floor from 11th floor.
11+19 = 30th floor.
Aman kumar said:
6 years ago
First find HCF of 57 and 63 = 3.
That means 3 is the highest factor that divides both exactly.
So, David will cover = 11+ 57/3= 30th.
Floor. same as albert= 51-63/3= 30th floor.
That means 3 is the highest factor that divides both exactly.
So, David will cover = 11+ 57/3= 30th.
Floor. same as albert= 51-63/3= 30th floor.
(3)
Spencer said:
1 decade ago
I do not understand the concept. Please help me in another way if possible.
Kulbhushan said:
1 decade ago
Because the floors are decreasing as he is coming down from 57th floor.
Lavanya said:
1 decade ago
Why they are considered only number of floors covered by David ?
Kavi said:
7 years ago
@Monika.
Your exaplanation will be exactly right thank you.
Your exaplanation will be exactly right thank you.
(1)
Latha said:
1 decade ago
Please any one explain why don't we write 51+63a?
Anonymous said:
8 years ago
Thanks for the explanation, it was very useful.
(1)
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