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 average of 25 person be x
total age of a person=average×no.of person
total age of 25 person=X×25
=25X
when a new person of 46kg come average decrease by 5kg(X-5)
Total age of 26 person =25x+46
Average age of 26 person=X-5
A/Q
.25X+46=26(X-5)
25X+46=26X-130
26X-25X=130+46
X =176
hence the av. of 25 person be 176kg
Either 4 or (-)4
Answer: 600m
Explanation:
Distance covered by Amar = 18/4.8 (1.6km) = 3/8(1600) = 600 m
Train speed 90 km /h
1st we have to change in m/s. then 90*5/18=25m/s
Then d=speed*time
=25*10=250m train length
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4
C. 4.8 mph
East
n+p
a
Out of 800 cheques 100 are for data processing.
Out of 16000 cheques = (100/800)*16,000 = 2000 cheques
1.6
23. 15s squre is 225and 8 squre is 64 addition is 289 product also 120 addition 15+8=23