To answer the question, 'Who is the youngest person in the group", which of the following statement is superfluous?

According to the question,
P > Q. S > R
T is least effective Q = R, S > Q
? S/P > Q = R > T
Now, it is given that P is less expensive than R and from the order, P is more effective than R. It means that P should be Purchased as it is more effective and less expensive than R

According to the question,
P > Q. S > R
T is least effective Q = R, S > Q
? S/P > Q = R > T
It is clear from the ranking order so obtained that brand S may be less effective than P, equal to P or more effective than P. It means that position of S is not fixed. Now as per question, sixth band i.e, M is more effective than S which implies that whatever be the position of S, there will be atleast four brands which will be less effective than M.

According to the question,
P > Q. S > R
T is least effective Q = R, S > Q
? S/P > Q = R > T
Statement V is not required.

According to the question,
P was more effective than Q.
1. P > Q.
The effectiveness of R was less than that of S.
2. S > R.
T was the least effective brand tested.
3. T is least effective.
Q and R were equally effective.
4. Q = R.
The effectiveness of S was greater than that of Q.
5. S > Q.

from 1 and 5 ,
6. S/P > Q .
from 6 and 4 ,
7. S/P > Q = R .
from 7 and 3 ,
? S/P > Q = R > T

R was less effective than p.

As per question for deadly,
U is more deadly than Z
1. U > Z.
V is less deadly than Z.
2. V < Z.
W is less deadly than U.
3. W < U.
X is more deadly than Y.
4. X > Y.
Y is more deadly than U.
5. Y > U.
Z is less deadly than W.
6. Z < W.

Now from 1 and 2,
7. U > Z > V
from 7 and 5,
8. Y > U > Z > V
from 4 and 8,
9. X > Y > U > Z > V
from 3, 6 and 9,
X > Y > U > W > Z > V

Effectiveness (deadly) X, Y, U, W, Z, V
Compound X is the most deadly.

As per given condition,
Arranging according to age,
Kamini is younger than Rupa.
1. K < R
Pooja is younger than Monika.
2. P < M
Rupa and Monika are of the same age.
3. R = M
Neelam is elder to Rupa.
4. N > R

From 1 and 2,
5. R = M >K or P
from 5 and 4,
6. N > R = M >K or P

Persons are arranged by Age
Neelm > Rupa = Monika > Pooja > Kamini
or Neelam > Rupa = Monika > Kamini > Pooja

Fourth position cannot be determined, if they are arranged in descending order of their ages.

As per given question,
According to height
Kamini is second in height.
A. 1--K--3--4--5
Pooja is taller than Monika.
B. P > M.
Rupa is tallest between them.
C. R will be at first position.
Neelam is taller than Pooja.
D. N > P

from A and C.
E. R--K--3--4--5
from B and D
F. N > P > M.
From F and E.
G. R > K > N > P > M
Neelam will be in the third position when persons are arranged in asecending order of height.

One side of road pole (left side) :: 1--2--3
other side of road pole (Right Side) :: 4--5--6
E, the tallest pole, is exactly opposite to the golden colored pole.
1. E-(Tallest) --- opposite to golden pole.
The shortest pole is exactly opposite to the metallic colored pole.
2. Shortest pole is opposite to metallic pole.
F, the black colored pole, is located between A and D.
3. pole position of one side of road will be A--F(Black)--D.
C, the bronze colored pole, is exactly opposite to A.
4. other side position of pole will be C(Bronze)--5--6.
B, the metallic colored pole, is exactly opposite to F.
5. other side position of pole will be C(Bronze)--B(Metallic)--6.
A, the white colored pole, is taller than C but shorter than D and B.
6. pole position of one side of road will be A(White)--F(Black)--D.

from 5 and 6,
7. other side position of pole will be C(Bronze)--B(Metallic)--E.
from 1,6 and 7.
8. pole position of one side of road will be A(White)--F(Black)--D(Golden).

The colour of tallest pole is silver.

One side of road pole (left side) :: 1--2--3
other side of road pole (Right Side) :: 4--5--6
E, the tallest pole, is exactly opposite to the golden colored pole.
1. E-(Tallest) --- opposite to golden pole.
The shortest pole is exactly opposite to the metallic colored pole.
2. Shortest pole is opposite to metallic pole.
F, the black colored pole, is located between A and D.
3. pole position of one side of road will be A--F(Black)--D.
C, the bronze colored pole, is exactly opposite to A.
4. other side position of pole will be C(Bronze)--5--6.
B, the metallic colored pole, is exactly opposite to F.
5. other side position of pole will be C(Bronze)--B(Metallic)--6.
A, the white colored pole, is taller than C but shorter than D and B.
6. pole position of one side of road will be A(White)--F(Black)--D.

from 5 and 6,
7. other side position of pole will be C(Bronze)--B(Metallic)--E.
from 1,6 and 7.
8. pole position of one side of road will be A(White)--F(Black)--D(Golden).
It cannot be established that which of the two poles B/D is taller but it is sure that either of B or D is the second tallest.

According to the question, sequence is as follows
Deepti > Sweta > Seema > Sohan > Seeta
So, Deepti is the eldest.