AmitBharatNo.of Days4540Efficiency2.22Percent(=145)2.5 Percent(=140)

Amit did the work in 56 days = 56×145×2=2845 

Therefore, Rest work 17/45 was done by Amit and Bharath = 174517360 = 8 days

( since Amit and Bharath  do the work in one day = 145+140=17360)

Let the length of the train be L metres and speeds of the train Arun and Sriram be R, A and S respectively, then 

       LR-A=36 ---------- (i) 

and LR+K=24 ---------(ii)

From eq.(i) and (ii)

              3(R - A ) = 2 (R + K) 

⇒  R = 3A + 2K 

In 30 minutes (i.e 1800 seconds), the train covers 1800R (distance) but the Arun also covers 1800 A (distance) in the same time. Therefore distance between Arun and Sriram, when the train has just crossed Sriram

               = 1800 ( R - A) - 24 ( A + K)

 Time required = 1800(R-A)-24(A+K)(A+K)

= (3600 - 24) = 3576 s                            

Let A, B, C be the events of getting a white ball in first, second and third draw respectively, then 

 Required probability = PA∩B∩C 

= PA PBA PCA∩B

 Now, P(A) = Probability of drawing a white ball in first draw = 4/18 = 2/9

When  a white ball is drawn in the first draw there are 17 balls left in the urn, out of which 3 are white

 ∴PBA=317 

Since the ball drawn is not replaced, therefore after drawing a white ball in the second draw there are 16 balls left in the urn, out of which 2 are white.

 ∴PCA∩B =216=18

 Hence the required probability = 29×317×18=1204

When the letters of the word BREAK are arranged in alphabetical order we get the new order of the letters as follows:
A  B  E  K  R
Thus, the letter E satisfies this criteria. This is third in either case whether in the word or in the alphabetical order.

It means that the first half of the alphabet is interchanged with second half of the alphabet. After making changes, nth letter from the left will be (n + 13)th letter of original series, ie English alphabet; If n is less than 14. But if n is more than 13, nth letter from left will be (n - 13)th letter from left.
In the given equation, we have to find out (13 - 7 =) 6th letter from right => (26 - 6 + 1 =) 21st letter from the left. Hence, required letter's position is more than 13; therefore the required letter is (21 - 13 =) 8th letter from left of original series, ie H.

Here specified letters are R, S, I, N and E following are the words formed with the help of the above letters:
1. RESIN    2. RISEN  3. RINSE   4. SIREN