Let’s assume the length of each train is ‘L’ and the speeds of the two trains are ‘V₁’ and ‘V₂’ respectively.
When the trains are moving in the opposite direction, their relative speed is the sum of their individual speeds. The total distance they need to cover is the sum of their lengths. Since they cross each other completely in 5 seconds, we can set up the following equation:
(V₁ + V₂) × 5 = 2L
When the trains are moving in the same direction, their relative speed is the difference between their individual speeds. The total distance they need to cover is the difference between their lengths. Since they cross each other completely in 15 seconds, we can set up the following equation:
(V₁ – V₂) × 15 = 2L
Now, let’s solve these equations to find the ratio of their speeds.
From the first equation, we have:
(V₁ + V₂) × 5 = 2L
V₁ + V₂ = (2L) / 5
From the second equation, we have:
(V₁ – V₂) × 15 = 2L
V₁ – V₂ = (2L) / 15
Let’s add these two equations together:
V₁ + V₂ + V₁ – V₂ = (2L) / 5 + (2L) / 15
2V₁ = (6L + 2L) / 15
2V₁ = (8L) / 15
V₁ = (4L) / 15
So, the speed of the first train is (4L) / 15.
Now, let’s substitute this value back into the first equation to find V₂:
(4L) / 15 + V₂ = (2L) / 5
V₂ = (2L) / 5 – (4L) / 15
V₂ = (6L – 4L) / 15
V₂ = (2L) / 15
Therefore, the speed of the second train is (2L) / 15.
The ratio of their speeds is given by:
(V₁ / V₂) = ((4L) / 15) / ((2L) / 15)
(V₁ / V₂) = 4L / 2L
(V₁ / V₂) = 2
So, the ratio of their speeds is 2:1.
Let the number be X,
Instead of dividing the number by 10, i.e.,X*10.
he got the result as 100,
so, (X*10)=100
X=100/10
X=10.
BUt he has to divide X by 10,
so, X/10=10/10=1.
obviously the answer is 1.
7
LET ACTUAL PRICE BE 100 RS(FOR CONVINIENCE)
THEREFORE IF PRICE IS CUT BY 20%
THEREFORE NEW PRICE=100-20=80 RS
THEREFORE WE NEED TO ADD X% TO 80 RS TO MAKE IT 20 RS AND ADD IT TO 80 TO MAKE IT 100RS
THEREFORE, 80X/100 = 20
I.E. 4X/5=20
THEREFORE x=20*5/4
=5*5
=25
HENCE 25% OF PRICE SHOULD BE ADDED TO MAKE THE PRICE EQUAL TO THE ACTUAL PRICE.
Answer: 1 / 3
Lets say each brand had 16 laptops
So Sold : A = 3 , B= 1 and C = 12 , total sold: 16 ,
Since each brand has 16 , total = 48
so 16/ 48 = 1/3 is the sold fraction
Monday
answer is 306.04
bogus, counterfeit, fake, false, illegitimate, sham, unreal
X-Y=-1
The definition of left and right depends on the observer and
is reversed when facing the opposite direction. The
definition of up and down does not depend on the orientation
of the observer.
Statements :
All film stars are playback singers. All film directors are film stars.
Conclusions :
I. All film directors are playback singers.
II. Some film stars are film directors.
Both conclusion follows
Indira Gandhi
9936
21
Bus started at 8:00
it travelled with 18mph…
distance of destination is 27 miles…
we know velocity=(distance)/time
i.e., time=27/18hours=3/2hours=90 min…
i.e., the bus reached destination at 9:30
the bus stayed for 30 min…
so the bus started return journey at 10:00
now the bus returned with velocity 18 + (18/2)=27mph
the taken to the bus to travel = 27/27=1 hour = 60 min…
so bus would be returned on 11:00…
39/50