Durham district school board Interview Questions, Process, and Tips

4 1 1 4
5 1 1 4
+ 0 1 1 4
———-
9 3 4 2

Chambal

D

200

Error is at 48. Correct once is 58

Take 5 pills from jar 1, 4 pills from jar2,…. and 1 pill
from jar 5 and put altogether in the scale. the ideal
weight should be (1+2+3+4+5)x10= 150gms. for eg if the jar2
is contaminated then the weight will be 146 gms. so
depending on the amount of weight loss we can identify the
contaminated jar.

X filling rate is 1/18 or 4/72 per hour

Y filling rate is 1/24 or 3/72 per hour

Combined as a pair it’s 7/72 in a complete 2 hour alternating sequence

72+ 7/72 =10 sequences = 70/72 on 20 hours, The outstanding balance is just 2/72

So at 20.5 hours with X turn filling is 100% complete with 72/72

Answer: It will take 20.5 hours to completely fill this tank.

Analysis of measured filling process, from X = 42/72 share & from Y = 30/72 share

It is assumed to be constant. Now, to cross past the pole, the train should cover a distance of x meters. Now, the time taken by the train to cross a platform of length 100 m is 25 seconds. Hence, the length of the train is 150 m.

5 is the answer….
Remaining all are the multiples of 3 expect 5

Let A, B and C be the three 6-faced dice.
Then, according to the question,
Since two dices has to be equal, that value can be any of the 6 faces, i.e., 6C1​ cases.
Now for each case, 2 equal dices can be selected from 3 dices in 3C2​ i.e., 3 ways.
And for each of the above, the third dice can have any of the 5 remaining faces
The possible outcomes are P(A)=61​,P(B)=61​,P(C)=65​,P(A)=61​,P(B)=65​,P(C)=61​ and P(A)=65​,P(B)=61​,P(C)=61​
Hence the required probability = 61​×61​×65​×6×3=21690​=125​