Spare Code Interview Questions, Process, and Tips

we can draw 12 tangents, 4 for 2 circles and 12 for 3
circles

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.

740

saying 20%alcohol in 15 litre solution.

It means (20/100)*15=3 litres

Now 5 litre of water is added not alcohol.

So it means only the volume of solution is increases by 5 not alcohol.

It means 15+5=20

Now % of alcohol is

(3/20)*100=15%.

Gain=(profit/c.p)*100

Gain =selling price-cost price =900-675
=225.
Gain=(225/675)*100.
=33.3%

5:6::7:10::6:5
=((5/6)/(7/10)/(6/5))
=((5/6)*(6/5)/(7/10))
=(1/(7/10))
=10/7

1

C. Every real number is a rational number.

In order to enhance my career, I asked my colleagues about my strength and weaknesses, the areas where I need to improve more, and acquired more knowledge from my superiors. I worked on my weaknesses to convert into a positive response.

(34/17)*3+34

here the 30% of 100 is 30
and 10% of the 30 = 3
so 20% = 6%
so ans = 6%