GATE Questions

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The probability of an impossible event is 0.

The event is known ahead of time to be not possible, therefore by definition in mathematics, the probability is defined to be 0 which means it can never happen.

The probability of a certain event is 1.

Let the principle amount be Rs. P

Interest rate = 12%

Total amount he paid after 5 years = Rs. 1280

ATQ, 

$$\begin{gathered} P + I = PTR100 + P \\ 1280 = PTR100 + 1 \\ 1280 = P5 x 12100 + 1 \\ 16P10 = 1280 \\ P = 80 x 10 = 800 \end{gathered}$$

Hence, the amount he borrowed = P = Rs. 800.

Given Karthik can cover the distance of 200 kms resting 2 hrs per day in 22 days.

Let the initial speed be '1'

Hence, Time = 22(24hrs - 2)

Noe new speed = 2/3

Let the number of days he take be 'D'

Therefore, 2224-2x3200=D24-2x2250

D = 11 x 3 x 5/4 = 41.25 days. = 41 1/4 days.

Here simple coding language has been used. Each letter has been assigned a numeric code and the respective code of letters are in the same order as the letters. 

Letter      B  E  L  M  O  P  R

Code         8  7  3  5  4  2  9

 BORE -> 8497 -- correct

 MOEP -> 5472 But given 5972 --- Incorrect

 LBOR -> 3849  -- correct

OMEP -> 4572  -- correct

Here distance d = 800 mts

speed s = 63 - 3 = 60 kmph = 60 x 5/18 m/s

time t = 800x1860x5= 48 sec.

P1+20100n > 2P 

Now, (6/5 x 6/5 x 6/5 x 6/5) > 2.

So, n = 4 years.

Total strength of the class is given by

15 + 44 + 4 + 3 - 1 = 65

The mother completes the job in x hours.
So, the daughter will take 2x hours to complete the same job.

In an hour, the mother will complete 1/x of the total job.
In an hour, the daughter will complete 1/2x of the total job.

So, if the mother and daughter work together, in an hour they will complete 1/x + 1/2x of the job.
i.e., in an hour they will complete 3/2x of the job.

The question states that they complete the entire task in 6 hours if they work together.
i.e., they complete 1/6 th of the task in an hour.

Equating the two information, we get 3/2x = 1/6
By solving for x, we get 2x = 18 or x = 9.

The mother takes 9 hours to complete the job.