Books: A, B, C, D, P, Q, R and S.

1) There are three 3 books kept between A & R.

2) Book P is just below to book R.

3) There are two books kept between P & S.

(Here case – 4 will gets eliminated)

4) There are as many books between B & D as R & A.

5) Book B is above book D.

6) Book C is immediate above to D and neither D nor A  is  at the lowermost rack.

Above combination will be the final combination.

As we can see in above table there are four books between R and Q.

Books: A, B, C, D, P, Q, R and S.

1) There are three 3 books kept between A & R.

2) Book P is just below to book R.

3) There are two books kept between P & S.

(Here case – 4 will gets eliminated)

4) There are as many books between B & D as R & A.

5) Book B is above book D.

6) Book C is immediate above to D and neither D nor A  is  at the lowermost rack.

1) Book C is kept 3 Book above to book A. ⇒ False

2) Two books kept between D and R ⇒ True

3) Book B is kept immediately above to R. ⇒ True

4) Book Q kept in the lowermost rack. ⇒ True

5) Book S is kept in topmost rack. ⇒ True

Books: A, B, C, D, P, Q, R and S.

1) There are three 3 books kept between A & R.

2) Book P is just below to book R.

3) There are two books kept between P & S.

(Here case – 4 will gets eliminated)

4) There are as many books between B & D as R & A.

5) Book B is above book D.

6) Book C is immediate above to D and neither D nor A  is  at the lowermost rack.

As Q is kept in lowermost rack therefore there will be 7 book above to the book Q.

Books: A, B, C, D, P, Q, R and S.

1) There are three 3 books kept between A & R.

2) Book P is just below to book R.

3) There are two books kept between P & S.

(Here case – 4 will gets eliminated)

4) There are as many books between B & D as R & A.

5) Book B is above book D.

6) Book C is immediate above to D and neither D nor A  is  at the lowermost rack.

As we can see in above arrangement Books A, C, R and S are at even number rack but book B is at odd number rack. (Considering bottom to top)

Books: A, B, C, D, P, Q, R and S.

1) There are three 3 books kept between A & R.

2) Book P is just below to book R.

3) There are two books kept between P & S.

(Here case – 4 will gets eliminated)

4) There are as many books between B & D as R & A.

5) Book B is above book D.

6) Book C is immediate above to D and neither D nor A  is  at the lowermost rack.

Hence, Q is at lowermost rack.

1) Box having Perfume is at the top of the stack.

2) There are four boxes between box having Watch and box having Perfumes.

3) There is one box between box having Watch and box having Mobile phone.

3) Box having Mobile phone is stacked immediately below box having Pendrive.

4) There are three boxes between box having Pendrive and box having Dongle.

5) Box having Bluetooth device is stacked immediately below box having Dongle.

6) Box having Headphones is placed immediately below box having Mobile phone. 

7) There are two boxes between box having Headphones and box having Power bank.

This eliminates Case 2.1

8) Box having Power bank is above box having Bluetooth device.

This eliminates case 2.2. Hence, Case 1 is the final arrangement.

1) Box having Perfume is at the top of the stack.

2) There are four boxes between box having Watch and box having Perfumes.

3) There is one box between box having Watch and box having Mobile phone.

3) Box having Mobile phone is stacked immediately below box having Pendrive.

4) There are three boxes between box having Pendrive and box having Dongle.

5) Box having Bluetooth device is stacked immediately below box having Dongle.

6) Box having Headphones is placed immediately below box having Mobile phone. 

7) There are two boxes between box having Headphones and box having Power bank.

This eliminates Case 2.1

8) Box having Power bank is above box having Bluetooth device.

This eliminates case 2.2. Hence, Case 1 is the final arrangement.

Hence, Perfume and Bluetooth device boxes are placed at the top and bottom of the stack.

1) Box having Perfume is at the top of the stack.

2) There are four boxes between box having Watch and box having Perfumes.

3) There is one box between box having Watch and box having Mobile phone.

3) Box having Mobile phone is stacked immediately below box having Pendrive.

4) There are three boxes between box having Pendrive and box having Dongle.

5) Box having Bluetooth device is stacked immediately below box having Dongle.

6) Box having Headphones is placed immediately below box having Mobile phone. 

7) There are two boxes between box having Headphones and box having Power bank.

This eliminates Case 2.1

8) Box having Power bank is above box having Bluetooth device.

This eliminates case 2.2. Hence, Case 1 is the final arrangement.

Hence, there are three boxes between Headphones and Perfume boxes.

1) Box having Perfume is at the top of the stack.

2) There are four boxes between box having Watch and box having Perfumes.

3) There is one box between box having Watch and box having Mobile phone.

3) Box having Mobile phone is stacked immediately below box having Pendrive.

4) There are three boxes between box having Pendrive and box having Dongle.

5) Box having Bluetooth device is stacked immediately below box having Dongle.

6) Box having Headphones is placed immediately below box having Mobile phone. 

7) There are two boxes between box having Headphones and box having Power bank.

This eliminates Case 2.1

8) Box having Power bank is above box having Bluetooth device.

This eliminates case 2.2. Hence, Case 1 is the final arrangement.

Hence, Watch box is third from the bottom of the stack.

1) Box having Perfume is at the top of the stack.

2) There are four boxes between box having Watch and box having Perfumes.

3) There is one box between box having Watch and box having Mobile phone.

3) Box having Mobile phone is stacked immediately below box having Pendrive.

4) There are three boxes between box having Pendrive and box having Dongle.

5) Box having Bluetooth device is stacked immediately below box having Dongle.

6) Box having Headphones is placed immediately below box having Mobile phone. 

7) There are two boxes between box having Headphones and box having Power bank.

This eliminates Case 2.1

8) Box having Power bank is above box having Bluetooth device.

This eliminates case 2.2. Hence, Case 1 is the final arrangement.

There is one box placed between all the pairs except Pendrive and Watch.

Ten boxes: P, Q, R, S, T, U, V, W, X and Y

Ten items: Books, Diaries, Copies, Stickers, Scales, Erasers, Pens, Pencils, Papers and Highlighters.

1) The box of Diaries is kept at the bottom and the box of Books is kept at the top.

2) There are four boxes kept between the box of Books and the box of Papers.

3) Box U contains Pens and is kept just below the topmost box.

4) Box T which contains Highlighters is kept immediately above the box of Diaries.

5) There are seven boxes kept between Box T and Box P.

6) There are two boxes between Box T and Box W which contains Papers.

7) There are four boxes between Box R and Box Y which contains Diaries.

8) Box Q which contains Pencils is kept immediately above Box V which contains Scales.

9) Box V is kept immediately above Box R.

10) Box S which contains Copies is kept immediately above Box X which contains Erasers.

Ten boxes: P, Q, R, S, T, U, V, W, X and Y

Ten items: Books, Diaries, Copies, Stickers, Scales, Erasers, Pens, Pencils, Papers and Highlighters.

1) The box of Diaries is kept at the bottom and the box of Books is kept at the top.

2) There are four boxes kept between the box of Books and the box of Papers.

3) Box U contains Pens and is kept just below the topmost box.

4) Box T which contains Highlighters is kept immediately above the box of Diaries.

5) There are seven boxes kept between Box T and Box P.

6) There are two boxes between Box T and Box W which contains Papers.

7) There are four boxes between Box R and Box Y which contains Diaries.

8) Box Q which contains Pencils is kept immediately above Box V which contains Scales.

9) Box V is kept immediately above Box R.

10) Box S which contains Copies is kept immediately above Box X which contains Erasers.

Hence, Box R contains Stickers.

Ten boxes: P, Q, R, S, T, U, V, W, X and Y

Ten items: Books, Diaries, Copies, Stickers, Scales, Erasers, Pens, Pencils, Papers and Highlighters.

1) The box of Diaries is kept at the bottom and the box of Books is kept at the top.

2) There are four boxes kept between the box of Books and the box of Papers.

3) Box U contains Pens and is kept just below the topmost box.

4) Box T which contains Highlighters is kept immediately above the box of Diaries.

5) There are seven boxes kept between Box T and Box P.

6) There are two boxes between Box T and Box W which contains Papers.

7) There are four boxes between Box R and Box Y which contains Diaries.

8) Box Q which contains Pencils is kept immediately above Box V which contains Scales.

9) Box V is kept immediately above Box R.

10) Box S which contains Copies is kept immediately above Box X which contains Erasers.

Hence, Box X is kept exactly between Box S and Box T.

Ten boxes: P, Q, R, S, T, U, V, W, X and Y

Ten items: Books, Diaries, Copies, Stickers, Scales, Erasers, Pens, Pencils, Papers and Highlighters.

1) The box of Diaries is kept at the bottom and the box of Books is kept at the top.

2) There are four boxes kept between the box of Books and the box of Papers.

3) Box U contains Pens and is kept just below the topmost box.

4) Box T which contains Highlighters is kept immediately above the box of Diaries.

5) There are seven boxes kept between Box T and Box P.

6) There are two boxes between Box T and Box W which contains Papers.

7) There are four boxes between Box R and Box Y which contains Diaries.

8) Box Q which contains Pencils is kept immediately above Box V which contains Scales.

9) Box V is kept immediately above Box R.

10) Box S which contains Copies is kept immediately above Box X which contains Erasers.

Hence, there are 4 boxes kept below Box W.

Ten boxes: P, Q, R, S, T, U, V, W, X and Y

Ten items: Books, Diaries, Copies, Stickers, Scales, Erasers, Pens, Pencils, Papers and Highlighters.

1) The box of Diaries is kept at the bottom and the box of Books is kept at the top.

2) There are four boxes kept between the box of Books and the box of Papers.

3) Box U contains Pens and is kept just below the topmost box.

4) Box T which contains Highlighters is kept immediately above the box of Diaries.

5) There are seven boxes kept between Box T and Box P.

6) There are two boxes between Box T and Box W which contains Papers.

7) There are four boxes between Box R and Box Y which contains Diaries.

8) Box Q which contains Pencils is kept immediately above Box V which contains Scales.

9) Box V is kept immediately above Box R.

10) Box S which contains Copies is kept immediately above Box X which contains Erasers.

Hence, there are 4 boxes kept between the box containing Pencils and the box containing Erasers.