SSC CGL Undated PYQs

Question 1

__________ refers to the number of births during a given period in the population that are added to the initial density.

Accepted Answer

Natality refers to the birth rate within a population over a specific period, which directly increases the initial population density. Mortality decreases it, while immigration relates to movement.

Question 2

If an equilateral triangle has side 12 cm, then what is the difference (in cm) between the circumradius and inradius?

Accepted Answer

For an equilateral triangle, circumradius R = a/√3 and inradius r = a/(2√3). The difference is a/(2√3). With a=12, difference = 12/(2√3) = 6/√3 = 2√3 cm.

Question 3

If a taxi going at 40 km/hr takes 25 minutes to travel a certain distance, by how much should it increase its speed (in km/hr) to travel the same distance in 20 minutes?

Accepted Answer

Since distance is constant, S1 × T1 = S2 × T2. So, 40 × 25 = S2 × 20, making the new speed 50 km/hr. The required increase is 50 - 40 = 10 km/hr.

Question 4

The areas of two similar triangles ΔXYZ and ΔPQR are 100 sq cms and 25 sq cms respectively. If PQ = 4 cm then what is the length of XY (in cm)?

Accepted Answer

The ratio of areas of similar triangles equals the square of the ratio of their corresponding sides. So, 100/25 = (XY/4)². This gives 4 = XY²/16, meaning XY² = 64, hence XY = 8 cm.

Question 5

What is the value of 9991 x 10009?

Accepted Answer

Use the identity (a-b)(a+b) = a² - b². Rewrite as (10000 - 9)(10000 + 9). This equals 10000² - 9², which is 100000000 - 81 = 99999919.

Question 6

At 20% discount the selling price of an article is Rs 2400, what is the selling price (in Rs) if the discount is 32.5%?

Accepted Answer

Let Marked Price be MP. 80% of MP = 2400, so MP = 3000. The new selling price at 32.5% discount is 67.5% of 3000, which equals 2025.

Question 7

Amazon river flows through which of the following country? ?

Accepted Answer

The Amazon River is located in South America. It primarily flows through Brazil, Peru, and Colombia, making Brazil the correct answer among the given options.

Question 8

Process of loosing electrons is known as _____.

Accepted Answer

Oxidation is the chemical process where an atom, molecule, or ion loses one or more electrons, resulting in an increase in its oxidation state.

Question 9

How many states does India have as of June 2017?

Accepted Answer

As of June 2017, India had 29 states. Telangana was formed as the 29th state in 2014. The number later reduced to 28 in 2019.

Question 10

In the following question, select the missing number from the given series. 3, 8, 5, 27, 8, 64, 12, 125, 17, ?

Accepted Answer

The series alternates. Odd positions increase by +2, +3, +4, +5. Even positions are cubes of consecutive numbers: 2³, 3³, 4³, 5³. The missing number is 6³ = 216.

Question 11

Constituent Assembly of India was founded in the year ________.

Accepted Answer

The Constituent Assembly of India was formed in December 1946 under the Cabinet Mission Plan to draft the Constitution of India. Its first meeting was held on December 9, 1946.

Question 12

The melting point of ice is ____ K.

Accepted Answer

The melting point of ice is 0°C. To convert Celsius to Kelvin, we add 273.15. The exact triple point of water is 273.16 K, which is often used as the standard.

Question 13

If a3 + b3 = 35 and ab = 6, then what is the value of a + b?

Accepted Answer

Guess values for a and b. Since ab = 6 and a³ + b³ = 35, a = 2 and b = 3 fit perfectly (8 + 27 = 35). Thus, a + b = 2 + 3 = 5.

Question 14

If a - b = 2 and ab = 8, then what is the value of a3 - b3?

Accepted Answer

Use the algebraic identity a³ - b³ = (a - b)³ + 3ab(a - b). Substitute the given values: 2³ + 3(8)(2) = 8 + 48 = 56.

Question 15

Which type of forests majorly comprises of lichens and mosses? ?

Accepted Answer

Tundra biomes have extremely cold temperatures and permafrost, preventing large tree growth. Therefore, their vegetation is primarily limited to low-growing plants like mosses and lichens.

Question 16

PQ is a diameter of a circle with centre O. RS is a chord parallel to PQ subtends an angle of 40° at the centre of the circle. If PR and QS are produced to meet at T, then what will be the measure (in degrees) of ∠PTQ?

Accepted Answer

The angle formed by two secants intersecting outside a circle is half the difference of the intercepted arcs. Thus, ∠PTQ = (Arc PQ - Arc RS) / 2 = (180° - 40°) / 2 = 70°.

Question 17

If 7x - (3/2) * (4x - 9) = 6.5, then the value of x is?

Accepted Answer

Expand the bracket: 7x - 6x + 13.5 = 6.5. Simplify to get x + 13.5 = 6.5. Subtracting 13.5 from both sides gives x = -7.

Question 18

Akshar remembers that the match is after 26th April but before 30th April, while Suresh remembers that the match is after 22nd April but before 28th April. On which date of April is the match?

Accepted Answer

Akshar's possible dates are 27, 28, 29. Suresh's possible dates are 23, 24, 25, 26, 27. The only common date satisfying both conditions is 27th April.

Question 19

What is the percentage increase in the number of audience in Screen 1 from second show to third show?

Accepted Answer

The audience doubled from the second to the third show. A 100% increase means the final value is exactly twice the initial value. Formula: ((Final - Initial) / Initial) × 100.

Question 20

Two smaller circles touch a large circle internally and pass through the center O of the larger circle. If the diameter of the bigger circle is 28 cm, then what is the area of the bigger circle which is not enclosed by the two smaller circles (in cm2)?

Accepted Answer

Bigger circle radius is 14 cm, area = 616 cm². Smaller circles have diameter 14 cm (radius 7 cm), area = 154 cm² each. Unenclosed area = 616 - 2(154) = 308 cm².