Question

J, K, L, M, N, O and P live on seven different floors of a building but not necessarily in the same order. The lower most floor of the building is numbered 1, the one above that is numbered 2 and so on till the topmost floor is numbered 7. Each one of them also likes a different subject namely- English, History. Commerce, Biology, Accounts, Geography and Computer, (but not necessarily in the same order).

If all the people are made to sit in alphabetical order from top to bottom, the positions of how many people will remain unchanged?

• A. Four
• B. None
• C. Two
• D. One
• E. Three

Answer 1

The correct option is B None

Seven people liveson seven different floor of a building. Each one of them likes a different subject of his choice.
According to the question.
J lives on an odd numbered floor except floor number 3.
Possibility for J $\to$ (1.5. 7)
The one who like Account lives immediately above J.
$\frac{?}{\underset{–}{J}}\to Account$
Only two people live between M and the one who likes Account.
$\underset{–}{M}$ ____ ____$\frac{}{Account}$
The one who likes history lives on odd numbered floor above M.
$\frac{?}{\uparrow }\to HistoryM$
Only three people live between L and the one who likes History.
$\frac{?}{History}----\underset{–}{L}$
The one who likes Commerce lives immdiately above L
$\frac{?}{L}\to Commerce$
P lives on an odd numbered floor.
Possiblity for P(1,3,5,7). One who likes English lives immediately above the one who likes computer.
$\underset{–}{English}\underset{–}{Computer}$
Only one person lives between K and N and K lives on one of the floors above N.
$\underset{–}{k}-\underset{–}{N}$
J does not like Biology and N does not like Commerce.
According to the given information, persons, their corresponding floor and subjects are given below.
$\begin{array}{ccc}Floors& Persons& Subjects\\ 7& P& History\\ 6& O& English\\ 5& M& Computer\\ 4& K& Commerce\\ 3& L& Biology\\ 2& N& Accounts\\ 1& J& Geography\end{array}$

$\begin{array}{cc}Oldposition& Arrangementin\\ & Alphabeticalorder\\ P& J\\ O& K\\ M& L\\ K& M\\ L& N\\ N& O\\ J& P\end{array}$

None of them remain unchanged.