Cognita schools Interview Questions, Process, and Tips

When none of the digits are repeated:

The hundred’s place can be filled by any of the digits: 2, 3, 5, 6, 7 or 8 except the one which has already been used at the thousand’s place, so it can be filled in 5 ways.

Similarly tens’ place can be filled in 4 ways: only those 4 numbers which have not been use either at hundred’s or thousand’s place.
Unit’s place can be filled in only 3 ways. So, total number of nos. Possible =4×5×4×3= 240

2a; 2a+2; 2a+4; 2a+6; 2a+8; 2a+10

t_2 + t_6 = 24 => 2a+2 + 2a + 10 = 24 => a = 3

therefore t_4 = 2(3) + 6 = 12

11

Explanation:
They should share the profits in the ratio of their investments.
The ratio of the investments made by A and B =
6000 : 8000 => 3:4

b

b

trick
(r/10)*(r/10)
(20/10)*(20/10)
4% decrese

10%

7 min clock:|——-7——-|
4 min clock:|—–4—-|—-4—–|—–4—-|—–4—-|
you got 9 min: |—————9————–|

1/2 Hr -> 80 Cheques
Per Hour -> 80 * 2 = 160
For 7 Hours -> 160 * 7 = 1120
For 7 1/2 Hour -> 1120 + 80 = 1200
clerk can process 1200 cheques in Sever & one half an hour day.

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.

around 29.8

6.25

#1: N = 1, f(N) = 1
#2: N = 199981, f(N) = 199981
#3: N = 199982, f(N) = 199982
#4: N = 199983, f(N) = 199983
#5: N = 199984, f(N) = 199984
#6: N = 199985, f(N) = 199985
#7: N = 199986, f(N) = 199986
#8: N = 199987, f(N) = 199987
#9: N = 199988, f(N) = 199988
#10: N = 199989, f(N) = 199989
#11: N = 199990, f(N) = 199990
#12: N = 200000, f(N) = 200000
#13: N = 200001, f(N) = 200001
#14: N = 1599981, f(N) = 1599981
#15: N = 1599982, f(N) = 1599982

Let length of tunnel is x meter
Distance = 800+x meter
Time = 1 minute = 60 seconds

Speed = 78 km/hr = 78*5/18 m/s = 65/3 m/s

Distance = Speed*Time
=>800+x=653∗60=>800+x=20∗65=1300=>x=1300−800=500

190 sec