Mental Ability, Analytical and Logical Reasoning (UPSC) Part-II

Total Questions: 50

21. Consider the following argument : "In order to be a teacher one must graduate from college. All poets are poor. Some Mathematicians are poets. No college graduate is poor." [2011-II]

Which one of the following is not a valid conclusion regarding the above argument?

Correct Answer: (b) Some teachers are not Mathematicians.
Solution:We can draw the following two diagrams from given arguments

From case II, the option (b) is not a valid conclusion.

22. The houses of A and B face each other on a road going north-south, A's being on the western side. A comes out of his house, turns left, travels 5 km, turns right, travels 5 km to the front of D's house. B does exactly the same and reaches the front of C's house. In this context, which one of the following statements is correct? [2011-II]

Correct Answer: (c) The houses of C and D are less than 20 km apart.
Solution:

Given information diagrammatically can be shown as follows:

Distance between C and D house

= √(10)² + (10)² = 10√2 km
= 14.14 km

From the above diagram, it is clear that the houses of C and D are less than 20 km apart.

23. Consider the following figures: [2011-II]

           

What is the missing number?

Correct Answer: (c) 9
Solution:

24. Study the following figure: [2011-II]

A person goes from A to B always moving to the right or downwards along the lines. How many different routes can he adopt?

Select the correct answer from the codes given below:

Correct Answer: (c) 6
Solution:

Different routes can be shown as follows:

These routes are:
A 1 2 B,    A 1 4 5 B,
A 1 4 7 B,   A 3 4 5 B
A 3 4 7 B,   A 3 6 B

25. Consider the following figure and answer the item that follows: [2011-II]

What is the total number of triangles in the above grid ?

Correct Answer: (c) 23
Solution:Let the side of the smallest triangle be 1 unit, then:
number of the smallest triangle (with side 1 unit)=12
number of triangles with side 2 units = 7
number of triangles with side 3 units = 3
number of triangles with side 4 units = 1
Total number of triangles in given grid = 12 + 7 + 3 + 1 = 23

26. Consider the figure given below and answer the items that follows: [2011-II]

In the figure shown above, OP 1 and OP 2 are two plane mirrors kept perpendicular to each other. S is the direction of a beam of light falling on the mirror OP 1. The direction of the reflected beam of light from the mirror OP 2 will be

Correct Answer: (c) Opposite and parallel to the direction S.
Solution:

In the above figure, dotted line shows the reflected beam of light from mirror OP₂.

27. A person stood alone in a desert on a dark night and wanted to reach his village which was situated 5 km east of the point where he was standing. He had no instruments to find the direction but he located the polestar. The most convenient way now to reach his village is to walk in the [2022-I]

Correct Answer: (c) direction keeping the polestar to his left

28. Consider the following statements: [2022-II]

1. All artists are whimsical.

2. Some artists are drug addicts.

3. Frustrated people are prone to become drug addicts.

From the above three statements it may be concluded that

Correct Answer: (b) Some drug addicts are whimsical.
Solution:

Thus, some drug addicts are whimsical.

29. Examine the following statements: [2022-II]

1. Either A and B are of the same age or A is older than B.

2. Either C and D are of the same age or D is older than C.

3. B is older than C.

Which one of the following conclusions can be drawn from the above statements?

Correct Answer: (d) A is older than C
Solution:

Then either B & D are of same age or B is older than D and Both D & B is older than C. Thus A will older than C.

30. Examine the following statements: [2022-II]

1. Only those who have a pair of binoculars can become the members of the birdwatcher's club.

2. Some members of the birdwatcher's club have cameras.

3. Those members who have cameras can take part in photo-contests.

Which of the following conclusions can be drawn from the above statements?

Correct Answer: (b) All members of the birdwatcher's club have a pair of binoculars.
Solution:Having a pair of binoculars and be a member of the birdwatcher's club