 # (01 OCT 2020) – Logical Reasoning, 2nd Shift NTA UGC NET JRF Question paper, Answer key

1. A trader marks up the price of goods he sells by 50% and gives a discount of 20%. Besides this, he also weighs the goods by 20% less. What is the net profit he gets?

A. 20%
B. 25%
C. 40%
D. 50%

Explanation: Given trader marks up his goods by 50% i.e., marked price is 150
also given he gave a discount of 20% on 150 rupees
150 x (20/100)=30 discount
SP=150- 30= 120
x=(120/80)*100
x=150
He gains a profit of “50%”

2. Which of the following numbers are non-prime?
A. 11
B. 13
C. 19
D. 21
E. 15
Choose the correct answer from the options given below:

1. A and E only
2. B and C only
3. C and E only
4. D and E only

Explanation: Prime number: An integer with exactly two positive divisors: itself and 1.

3. Statement I: If the ratio of the speeds of A and B is a:b, then the ratio of the times taken by them to cover the same distance is b:a
Statement II: Suppose two men are moving in the same direction at u m/s and v m/s respectively, where u> v, then their relative speed is (u+v) m/s

Sub Points of Question if no sub points of question then leave
Options of Question with break tag 1. Both Statement I and Statement Il are true
2. Both Statement I and Statement il are false
3. Statement is I correct but Statement Il is false
4. Statement is I incorrect but Statement II is true

Explanation: In the same direction we subtract and in the opposite direction we add for relative speed.

4. Complete the following series:
9, 11, 15, 23, 39, __?

1. 71
2.65
3.44
4.68

Explanation: 2 4 8 16 32 gap.

5. Statement I: Sum of the angles of a triangle is 180°.
Statement II: The sum of any two sides of a triangle is greater than the third side.

1. Both Statement and Statement Il are true
2. Both Statement and Statement Il are false
3. Statement is correct but Statement Il is false
4. Statement is incorrect but Statement Il is true

Explanation: Triangle Properties
• Sum of all the angles of a triangle is equal to 180°.
• Sum of all exterior angles of any triangle is equal to 360°.
• Sum of the length of the two sides of a triangle is greater than the length of the third side.
• In the same way, the difference between the two sides of a triangle is less than the length of the third side.
• Exterior angle of a triangle is always equal to the sum of the interior opposite angles. Also known as an exterior angle property.
∠ACD is exterior angle to ∆ABC.
According to the exterior angle property, ∠ACD = ∠CAB + ∠ABC.
• Side opposite the greater angle is the longest side of all the three sides of a triangle.
• Two triangles are said to be similar if their corresponding angles of both triangles are congruent and lengths of their sides are proportional.
• Perimeter of a triangle = sum of all its three sides.

6. The product of the ages of Sagun and Srishti is 240. If twice the age of Srishti is more than Sagun’s age by 4 years, then what is Srishti’s age?

1.15
2.12
3. 10
4. 20

Explanation: x * y = 240 (Equation 1)
2y = x + 4
∴ x = 2y – 4
put above value of x in (Equation 1)
(2y – 4) * y = 240
2y^2 – 4y – 240 = 0
2y^2 – 24y + 20y – 240 = 0
2y(y – 12) + 20(y – 12) = 0
(y – 12)(2y + 20) = 0
y – 12 = 0 OR y = -20 / 2 = -10
y = 12 OR y = -10
Consider +ve age= 12
Or Put from y option in 2y^2 – 4y=240

7. Consider the following three sets of numbers:

A. 2, 5, 9 B. 1, 6, 10 C. 3, 4,8
Which of the following represents the correct ascending order of the averages of three sets A, B and C?

1. C < A < B
2. B < C < A
3. B < A < C
4. C < B < A

Explanation: A’ average: 16/3= 5.33; B= 17/3= 5.67; C= 15/3= 5

8. If 30% of A=0.25 of B=1/5 of C, then which of the following is true about A:B:C?

1. 10:11:12
2. 10:15:12
3. 10:12:15
4. 10:11:15

Explanation: 30% of A = 25% of B
30 A = 25 B
A : B = 25 : 30 = 5 : 6
Again, 25% of B = 20% of C
25 B = 20C
5B = 4C
B : C = 4 : 5
A : B = 5 : 6
B : C = 4 : 5
∴ A : B : C = 5 × 4 : 4 × 6 : 6 × 5 = 20 : 24 : 30 = 10 : 12 : 15

9. A man is facing south-west. If he turns 90° in the anticlockwise direction and then 135° in the clockwise direction, which direction is he facing now?

1. West
2. North-West
3. North-East
4. East

10.Today is what day if, the day before yesterday it was the 13th of the present month and the 3rd day of the last month, with 31 days, was a tuesday?

1. Sunday
2. Tuesday
3. Wednesday
4. Friday

Explanation: 13+2 = Today its 15th
3rd of last month= Tuesday, after every 7 days its tuesday
3 + 7= 10 similarly on 17, 24, 31st it tuesday
1st of this month Wed, 8, 15 its Wednesday
1. 2. 