Defence equipment & support (de&s) Interview Questions, Process, and Tips

A

Let 10’splace digit is x and unit’s place digit y

First milestone : 10x+y
Second milestone : 10y+x
Third milestone: 100x+y

Since the speed is uniform so
Distance covered in first Hr = Distance covered in Second Hr
(10y+x)-(10x+y) = (100x+y)-(10y+x)
After solving, we get —-> y=6x but since x and y are digits so only possible combination is x=1 and y=6,
So average speed = 45 KM/HR

47

Assume there are 52 weeks in one year.
Since he supposed to have a new order for every two weeks, he
needs 52/2 = 26 orders to break the office record.

Now after 28 weeks,he has got only 28/2 -6 = 8 orders.

Hence,he needs 26-8 = 18 new orders in the remaining 24= 52-28 weeks to break the office record.

Compute 24 orders/18 weeks = 4/3 orders/week ,
we see that averagely he has a new order for
every 4/3 weeks in the remaining weeks to break the office record.

B. The Secretary, Ministry of Finance is the right answer

14 km/h

suppose
pipe:
A -30 hours A’s effeciency (60/30) =2
60( lcm of 30 and 20)
B- 20 hours B’s effeciency (60/20)=3

time taken by both to fill = 60/5 =12 as given in question (effeciencies of both a+b =2+3=5)
time taken by faster pipe i.e b = 60/3 =20

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Lipimishra2

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Let the no. of men (originally) be x.
x no. of men require 10 days.

if however there were 10 men less it will take 10 days more for the work to be finished. ——> means x-10 men require 10+10=20 days.

10x = 20 (x-10)
x = 2x -20 => x = 20.

When A runs 1000 meters, B runs 900 meters and when B runs 800 meters, C runs 700 meters.

Therefore, when B runs 900 meters, the distance that C runs = (900 x 700)/800 = 6300/8 = 787.5 meters.

So, in a race of 1000 meters, A beats C by (1000 – 787.5) = 212.5 meters to C.

So, in a race of 600 meters, the number of meters by Which A beats C = (600 x 212.5)/1000 = 127.5 meters.