GATE CS 2021 | Set 2
Question 1 |
Gauri said that she can play the keyboard __________ her sister.
as well as | |
as better as | |
as nicest as | |
as worse as |
Discuss it
Question 1 Explanation:
‘worse’, ‘better’ are comparative words which need the word ‘than’ for comparison. Out of the remaining two options ‘as well as’ is the correct answer.
Correct Option (A).
Question 2 |


A | |
B | |
C | |
D |
Discuss it
Question 2 Explanation:
When the sheet is folded, the vertical lines of the sheet will be above than the horizontal lines.
So option (B) is true.
Question 3 |
If θ is the angle, in degrees, between the longest diagonal of the cube and any one of the edges of the cube, then, cosθ =
1/2 | |
1/√3 | |
1/√2 | |
√3/2 |
Discuss it
Question 3 Explanation:
We may assume the length of a side of the cube is 1.
Then the diagonal is given by the vector v = <1, 1, 1>.
The 3 sides are given by the vectors i = <1, 0, 0>, j = <0, 1, 0> and k = <0, 0, 1>.
Each gives the same angle.
Alternative Way :
cosθ = Base / Hypotenuse = a3√a=13√
Length of diagonal of a side = √(a2 + a2) = √(2a)
Length of the longest diagonal = √( a2 +(√(2a))2 ) = √(3)a = Hypotenuse
Therefore,
cosθ = Base / Hypotenuse = a/(√(3)a) = 1/√3



Question 4 |

2 | |
4 | |
6 | |
8 |
Discuss it
Question 4 Explanation:
Apply formula a2 - b2 = (a+b)*(a-b)
You will get x = 4.
Question 5 |
Pen : Write :: Knife : _______Which one of the following options maintains a similar logical relation in the above?
Vegetables | |
Sharp | |
Cut | |
Blunt |
Discuss it
Question 5 Explanation:
A pen is used to write. Similarly, a knife is used to cut. Correct Option (C)
Question 6 |
Listening to music during exercise improves performance and reduces discomfort. Scientists researched whether listening to music while studying can help students learn better and the results were inconclusive. Students who needed external stimulation for studying fared worse while students who did not need any external stimulation benefited from music.
Which one of the following statements is the CORRECT inference of the above passage?
Listening to music has no effect on learning and a positive effect on physical exercise | |
Listening to music has a clear positive effect both in physical exercise and on learning | |
Listening to music has a clear positive effect on physical exercise. Music has a positive effect on learning only in some students | |
Listening to music has a clear positive effect on learning in all students. Music has a positive effect only in some students who exercise |
Discuss it
Question 6 Explanation:
From the first statement “Listening to music during exercise improves exercise performance and reduces discomfort. “ It is clear that listening to music has a positive effect on physical exercise.
From the statement “Scientists researched whether listening to music while studying can help students learn better and the results were inconclusive. “ it is clear that only on some students music has a positive effect.
Question 7 |


A | |
B | |
C | |
D |
Discuss it
Question 7 Explanation:
When we join the missing piece, A rectangle should be formed. If we carefully notice the L shape part of the shape, we can easily eliminate option B and option D. Now if we notice option A and option C, option A is perfectly matching to complete the shape.
Question 8 |
The number of students in three classes is in the ratio 3:13:6. If 18 students are added to each class, the ratio changes to 15:35:21.
The total number of students in all the three classes in the beginning was:
22 | |
66 | |
88 | |
110 |
Discuss it
Question 8 Explanation:
According to given conditions,
3x+18 : 13x+18 : 6x+18 = 15 : 35 : 21
On solving,
(3x+18) / (13x+18) = 15/35
105x + 630 = 195x + 270
195x - 105x = 630 - 270
90x = 360
x = 360/90 = 4
So total number of students in these three classes,
3*4 = 12
13*4 = 52
6*4 = 24
In total, 88 students are there.
Question 9 |

4:3 | |
1:1 | |
3:4 | |
1:2 |
Discuss it
Question 9 Explanation:
From the above graph we obtained following information-
Year Cost/Unit Cost Price Number of Units 1 3 300 100 2 2 400 200 3 1 300 300
Let selling price of year 2 = SP2 and Selling price of year3 = SP3
Given that-
Taxes for year 2 = 13% of SP2 = 0.13SP2 Taxes for year 3 = 15% of SP3 = 0.15SP3 Cost per unit of year 3 = 1 (Cost per unit of year 2)/2 = 1 So now Cost / unit of year 2 = 2*1 = 2
Net profit formula now = Selling Price - (Cost Price + (Tax% x selling price )
For year 2
296 = SP2- (200*2 + 0.13*SP2) SP2 = 696*100/87 SP2 = 800
For year 3
210 = SP3 - (300*1+0.15*SP3) SP3 = 510*100/85 SP3 = 600
Required Ratio 800/600= 4/3 (Correct Option A)
Question 10 |
Six students P, Q, R, S, T and U, with distinct heights, compare their heights and make the following observations.
- Observation I: S is taller than R.
- Observation II: Q is the shortest of all.
- Observation III: U is taller than only one student.
- Observation IV: T is taller than S but is not the tallest.
T | |
R | |
S | |
P |
Discuss it
Question 10 Explanation:
From observations II and III, we can say that Q is the shortest. U is the second shortest.
__ __ __ __ U QFrom observations I and IV, we can say that T is the second tallest. S is the third tallest. R is the fourth tallest. Thus, P is the tallest. Therefore, the final arrangement is as follows,
P T S R U QThree students are taller than R, hence three students are shorter than S.
There are 65 questions to complete.