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A contour line joins locations having the same height above the mean sea level. The following is a contour plot of a geographical region. Contour lines are shown at $25$ m intervals in this plot. If in a flood, the water level rises to $525$ m, which of the villages $P, Q, R, S, T$ get submerged?

1. $P, Q$
2. $P, Q, T$
3. $R, S, T$
4. $Q, R, S$

edited

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Isn't 475 < R < 500

Height of each place will be ( in meters)

$600 > P >550,\quad 550 > Q > 525 ,\quad 500 >R > 450,\quad 450 > S > 425 ,\quad 525 >T> 500$

Only $R,S,T < 525$

Hence most suitable answer will be (c) R,S,T

These places will definitely be submerged if the water level rises to $525\;\text{m}.$

by

Absolutely right with a good explanation.

contour plot is representaion3-D diagram in 2-D plot.
representing a 3d diagram on a 2d  plot is a really cool thing, thanks to this GATE question I became aware of it.
For concept of contour plot,watch this video:

https://youtu.be/WsZj5Rb6do8
This Contour Line problem with a graphical picture   asked in each set this year ( both set 1 and set 2 papers) . In both sets  questions are logical only .

No prior experience is required to solve them other than logical mind .

Now coming to this set 1 question,
given water level value is 525 m .

600 > P >550,     550 > Q > 525 ,    500 >R > 450,     450 > S > 425  ,  525 >T> 500

now to get submerged the value should be Less than 525

that condition is satisfied by R, S, and T only . Because P and Q have above 525 value.

so the answer is R, S, T -- which is option C .
by

### 1 comment

550 >Q>525
The villages which are below the flood level of 525m are clearly R (<500m), S(between 425m and 450m) and T(between 500m and 525m). So (C) is correct.

However, village P is above 575m and village Q is between 525m and 550m.