GATE CS 2018


Question 1
What is the missing number in the following sequence? 2, 12, 60, 240, 720, 1440, .... 0
A
2880
B
1440
C
720
D
0
Arithmetic Aptitude    Numbers    Series    GATE CS 2018    
Discuss it


Question 1 Explanation: 
The series starts with 2. We multiply first term with 6 to get second term 12 Then we multiply second term with 5 to get third term 60 Then we multiply third term with 4 to get fourth term 340 Then we multiply fourth term with 3 to get fifth term 720 Then we multiply fifth term with 2 to get fifth term 1440. Then we need to multiply with 1 and we get 1440 again.
Question 2
What would be the smallest natural number which when divided either by 20 or by 42 or by 76 leaves a remainder ‘7’ in each case is_
A
3047
B
6047
C
7987
D
63847
General Aptitude    Arithmetic Aptitude    LCM    GATE CS 2018    
Discuss it


Question 2 Explanation: 
We need a number that can be written as 20x + 7, 42y + 7, 76z + 7 for three integers x, y and z. We basically need to find least common multiple of 20 (2 * 2 *5), 42(2 * 3 * 7) and 76(2 * 2 * 19) which is 2 * 2 * 5 * 3 * 7 * 19 = 20 * 21 * 19 = 420 * 19 = 7980 So our number is 7980 + 7 = 7987. Note - You can also verify options using virtual calculator.
Question 3
"From where are they bringing their books? _________ bringing _________ books from _________." The words that best fill the blanks in the above sentence are
A
Their, they're, there
B
They're, their, there
C
There, their, they're
D
They're, there,there
English    General Aptitude    GATE CS 2018    
Discuss it


Question 3 Explanation: 
"From where are they bringing their books? Who bringing Whose books from Where." Who - A group as subject = They are Whose - of that group = their Where - from a place = there "From where are they bringing their books? They are bringing their books from there." So, option (B) is correct choice.
Question 4
A __________ investigation can sometimes yield new facts, but typically organized once are more successful.
A
Meandering
B
Timely
C
Consistent
D
Systematic
English    General Aptitude    GATE CS 2018    
Discuss it


Question 4 Explanation: 
Meandering (as adjective) = proceeding in a convoluted or undirected fashion. Timely (as adjective) = done or occurring at a favourable or useful time; opportune. Consistent (as adjective) = acting or done in the same way over time, especially so as to be fair or accurate. Systematic (as adjective) = done or acting according to a fixed plan or system; methodical. Therefore, meandering is correct choice, all other options are similar to the word organized.
Question 5
The area of a square is ‘d’. What is the area of the circle which has the diagonal of the square as its diameter?
A
πd
B
πd2
C
(1/4) πd2
D
(1/2)πd
General Aptitude    Trigonometry & Height and Distances    GATE CS 2018    
Discuss it


Question 5 Explanation: 
circle-square
One important observation to solve 
the question :

Diagonal of Square = Diameter of Circle.

Let side of square be x. 

From Pythogorous theorem.
Diagonal = √(2*x*x)

We know area of square = x * x = d

Diameter = Diagonal =  √(2*d)

Radius = √(d/2)
Area of Circle = π * √(d/2) * √(d/2) = 1/2 * π * d

Question 6
In the figure below, ∠DEC+∠BFC is equal to _______ . GATE-CS-2018-Question
A
∠ BCD - ∠ BAD
B
∠ BAD + ∠ BCF
C
∠ BAD + ∠ BCD
D
∠ CBA + ∠ ADC
General Aptitude    Mensuration 2D    GATE CS 2018    
Discuss it


Question 6 Explanation: 
Option (A) is correct.
Question 7
In a party, 60% of the invited guests are male and 40% are female. If 80% of the invited guests attended the party and if all the invited female guests attended, what would be the ratio of males to females among the attendees in the party?
A
2:3
B
1:1
C
3:2
D
2:1
Set Theory & Algebra    General Aptitude    Ratio and Proportion    GATE CS 2018    
Discuss it


Question 7 Explanation: 
Let total males and females be 60x and
40x respectively.

Total number of people = (60x + 40x)
Total number of people who attended : 
                 0.8(60x + 40x) = 80x

Let y males attended. It is given all 
1females attended 

40x + y = 80x
y = 40x which is same as females.
Alternative Approach - Lets total number of people = 100. Therefore, 60 are male and and 40 are female. But total 80 guests are attended and all 40 female attended the party. So, there remaining (80 - 40 = 40) attendees should be male. Then the ration of male to female among attendees is 40 : 40 = 1 : 1
Question 8
A six sided unbiased die with four green faces and two red faces is rolled seven times. Which of the following combinations is the most likely outcome of the experiment?
A
Three green faces and four red faces.
B
Four green faces and three red faces.
C
Five green faces and two red faces.
D
Six green faces and one red face
Probability    General Aptitude    Arithmetic Aptitude    GATE CS 2018    
Discuss it


Question 8 Explanation: 
Considering uniformly distributed outcomes, we get 4 greens and 2 reds in six throws. Then in one more throw, green is more likely. So, option (C) is correct.
Question 9
If pqr ≠ 0 and p^{-x} = \frac{1}{q}, q^{-y} = \frac{1}{r}, r^{-z} = \frac{1}{p}, what is the value of the product xyz ?
A
-1
B
1 / pqr
C
1
D
pqr
General Aptitude    Arithmetic Aptitude    Algebra    GATE CS 2018    
Discuss it


Question 9 Explanation: 
Taking logs of given three values, we get
1/q = p-x -------(1)
1/r = q-y -------(2)
1/p = r-z -------(3)

1/q = p-x
    = r-xz [Putting value of p from (3)]
    = q-xyz  [Putting value of r from (2)]
    = 1 / qxyz

On comparing power of q both sides, we get xyz = 1
So, option (C) is correct.
Question 10
In appreciative of social improvement completed in a town, a wealthy philanthropist decided to give gift of Rs. 750 to each male senior citizen and Rs. 1000 for female senior citizens. There are total 300 senior citizens and th 8/9th of total men and 2/3rd of total women claimed the gift. What is amount of money philanthropist paid?
A
15000
B
200000
C
115000
D
151000
General Aptitude    Arithmetic Aptitude    Ratio and Proportion    GATE CS 2018    
Discuss it


Question 10 Explanation: 
Let there be x total men.

Total amount paid = x * 750 * 8/9 + (300 - x)*1000*2/3
                  = x*2000/3 + 300*1000*2/3 - x*2000/3
                  = 200000
There are 65 questions to complete.


My Personal Notes arrow_drop_up