Logical Reasoning and analytical ability is an important part of the CSAT. The number of questions asked for CSE paper-II from the logical reasoning and analytical ability portion is between 15 and 25.
Sample questions with solution
Examine the following statements.(2011)
1.All animals are carnivorous.
2.Some animals are not carnivorous.
3.Animals are not carnivorous.
4.Some animals are carnivorous.
Codes
(a) 1 and 3
(b) 1 and 2
(c) 2 and 3
(d) 3 and 4
Ans. (a)
Exp. Statements (1) and (2) as well as (3) and (4) are mutually contradicting pairs. Quantifiers ‘all’ and ‘no’ cannot be true at the same time but can be false at the same time. So, Statements (1) and (3) cannot be true at the same time but can be false together
2. Only six roads A, B, C, P, Q and R connect a military camp to the rest of the country. Only one out of A, P and R is open at any one time. If B is closed, so is Q. Only one of A and B is open during storms. P is closed during floods. In this context, which one of the following statements is correct? (2012)
(a) Under normal conditions only three roads are open
(b) During storms at least one road is open
(c)During floods only three roads are open
(d) During calamities all roads are close
Ans. (b)
Exp. Consider option (a), in this case, if R is open then B, C and Q can also be open. Hence, option (a) is not true. In storms either A or B is open. Hence, this statement is definately correct. During calamities at least one road is open. So, option (d) is not correct. two roads can be open. so option D is not correct
3.Examine the following statements.(2012)
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?
(a) All those who have a pair of binoculars are members of the birdwatcher’s club
(b)All members of the birdwatcher’s club have a pair of binoculars
(c) All those who take part in photo-contests are members of the birdwatcher’s club
(d) No conclusion can be drawn
Ans . (b)
Exp. Only those who have binoculars can be a part of birdwatcher’s club, hence, all the members of birdwatcher’s club will have binoculars for sure. But all those who have binoculars may not be part of birdwatcher’s club.
4.Consider the following statement. “Though quite expensive, television is not a luxury item, as one can learn many things through television (2012)
Which one of the following is a valid inference from the above statement?
(a All essential things for learning are not luxury
(b) All expensive things are regarded as luxury
(c)Television is essential for learning
(d) Television is not a luxury ite
Ans. (b)
Television is not luxury but one can learn various things from it. So, it can be inferred that all essential things for learning are not luxury
5. Consider the following statements. (2012)
1.All X-brand cars parked here are white.
2.Some of them have radial tyres.
3.All X-brand cars manufactured after 1986 have radial tyres.
4.All cars are not X-brand.
Which one of the following conclusions can be drawn from the above statements?
(a) Only white cars are parked here
(b) Some white X-brand cars with radial tyres are parked here
(c) Cars other than X-brand cannot have radial tyres
(d) Most of the X-brand cars are manufactured before 1986
Ans. (b)
EXP. All X-branded cars parked here are white and some of them have radial tyres. Hence, some white X-brand cars parked here have radial tyres.
6. Consider the following statements.
1. All machines consume energy. (2012)
2.Electricity provides energy. Electrically operated machines are cheap to maintain. Electrically operated machines do not cause pollution.
Which one of the following inferences can be drawn from the above statements?
(a) All machines are run by electric energy
(b) There is no form of energy other than electricity
(c) Most machines are operated on electric energy
(d) Electrically operated machine are preferable to use
Ans. (d)
Exp. From Statements (1) and (2), we can conclude that electricity is one of the mode and not the only mode for providing energy. So, options (a) and (b) are ruled out. Option (c) is not correct as it can’t be inferred from the statement. Statements (3) and (4), talk about two basic advantages of electrically operated machines. So, it can be inferred that electrically operated machines are preferable to use.
7“Liberty, therefore, is never real unless the government can be called to account when it invades rights.” (2014)
Which one of the following is the best justification of the above statement?
(a) In the realisation that the government can be brought to book in a court of law
(b) In identifying a man as a political unit in a way which distinguishes him from other citizens
(c) In a decentralised society wherein the basic needs of men can find satisfaction
(d) In the understanding that liberty and restraints are complementary
Ans. (a)
Exp. The question gives four statements to justify the given statement. The statement asks to judge the validity of the argument that liberty can never be real unless the government can be called to account, when it invades the rights. Only in statement (a), it is mentioned that government can also be brought to book in court of law. Hence, this provides the best justice
8.Consider the following statements.(2015)
1.Some claim to have seen UFOs (Unidentified Flying Objects).
2.Life on other heavenly bodies is considered to be a possibility.
3.Voyage to space is now an established fact.
From the above statements, it may be concluded that
(a) UFOs are heavenly bodies
(b) UFOs are sent from other heavenly bodies
(c) some living species in other heavenly bodies are more intelligent than man
(d) nothing definite can be said about the UFO
Ans. (d)
EXP. from he given statement , it may concluded that nothing definite can be said about the UFOs
9. Answer the questions no. 1 to no. 5 based on the based on the figure given below in which Rectangle represents Males, Circle represents the urbans, Square represents the educated and Triangle represents the civil servants.
Q1. The number indicating the uneducated urban males is
a. 5
b. 4
c. 1
d. 9
ANS : A
Uneducated: Exclude the numbers inside the square.
Educated: Numbers inside the Circle
Male: Numbers inside the Rectangle
Thus, 5 is the only number that satisfies the conditions.
Q2. The number indicating the educated urban males who are not civil servants is
a. 7
b. 8
c. 9
d. 10
ANS: C
Educated Urban Males: 8 and 9
As 8 represents the civil servants, 9 is the number that we are looking for.
Q3. The number indicating the educated civil servants who are males but not urban is
a. 7
b. 10
c. 8
d. 4
ANS: B
Educated civil servant Males: 10 and 8
Non urban: 10
Q4. The number indicating the educated males who are urban civil servants is
a.5
b. 4
c. 11
d. 8
ANS: D
Q5. The number indicating the uneducated females who are urban civil servants is
a. 11
b. 5
c. 9
d. 7
ANS: A
10. Ravi and Kumar are working on as assignment. Ravi takes 6 hours to type 32 pages on a computer, while Kumar takes 5 hours to type 40 pages. How much time will they take, working together on two difference computers to type an assignment of 110 pages?
A. 7 hours 30 minutes
B. 8 hours
C. 8 hours 15 minutes
D. 8 hours 25 minutes
ANS :C
Number of pages typed Rave in 1 hour =326=163 Number of pages typed by Kumar in 1 hour =405=8. Number of pages typed by both in 1 hour =(163+8)=403. ∴ Time taken by both to type 110 pages =(110×340) hours =814 hours (or) 8 hours 15 minutes.
