SSC 2020 Preparation: Quantitative Aptitude 2

SSC CGL new vacancy 2020 has Quantitative Aptitude paper in tier I and Tier II examination.

SSC Preparation: Number System

Whole Number: 0, 1, 2…n

Natural Number: 1, 2...n

Integers: -n… -2, -1, 0, 1, 2...n

Rational Numbers: if p and q are two integers and q≠0, then number in form of p/q is called rational number. Example: 3/2

Irrational Number: This cannot be written in form of p/q. Example: e

Real Number: This exists on number line. It includes all rational and irrational numbers. Example: 0, 1.

 Imaginary Number: Real numbers with imaginary number i. Example: 6i

Complex Number: Numbers represented in form of a + bi, where, bi is the imaginary part.

Prime Numbers: These are divided by only 1 or itself.

Example:  3

Note: 1 is not a prime number.

Relative Prime: This does not share any common factor other than 1. Example: 2 and 13

Even Number: These are divisible by 2. Example: 10

Odd Number: These are not divisible by 2. Example: 7

SSC Preparation: Mensuration

This technique is used to calculate area, perimeter and volume of different structures.

Formulas

1.  Triangle: If a, b and c are three different sides of a triangle, then

Area= √s(s-a) (s-b) (s-c)    where s= (a + b + c)/2

       Perimeter= a + b + c

·      If height and base of a triangle is given, then

                      Area=*bh

·      For equilateral triangle

     Perimeter =3a

      Area= a²

·      For right angle triangle

   Area=* base*height

Pythagoras theorem to calculate third side i.e. hypotenuse

  h²=p²+b², where p is perpendicular or height

2.  Rectangle:

Area= Length *breadth

Perimeter= 2* (length + breadth)

Diagonal of rectangle =√ (length) ²+ (breadth) ²

3.  Square:  All sides are equal.

Area= (side) ²

Perimeter= 4 * side

Diagonal= √2 * side

4.  Rhombus: All sides are equal but diagonals are different.

 Area= *d₁*d₂

Perimeter= 4* side

5.  Circle:

Area= π (radius) ² where radius= diameter/2

Circumference= 2π* radius

Perimeter of semicircle= π (radius) ²/2

6.  Cube: where all three sides are equal.

Volume= (side) ³

Surface Area= 6* (side) ²

Diagonal=√3 *side

7.  Sphere: it is in form of solid ball with radius r.

Volume=  π (radius) ²

Surface Area= 4 π (radius) ²

SSC Preparation: Data Interpretation

Tips:

·      Read and understand question carefully.

·      Analyze and sort the data first

·      Remember all the basic formulas like average, percentage, ratio, mean etc.

·      Fast calculation is the key.

·      Pay attention to units of data.

·      Approximate value where needed.

SSC Preparation: Time and work

More work can be done in same time if we deploy more people.

·      If X do a piece of work in N days, then X’s 1 day work is= 1/N

·      Part of work completed by X in T days= T/N

·      If X is N times as good in work as Y, then:

Ratio of work done by A and B = N: 1

Ratio of times taken by A and B to finish a work = 1: N

·      X and Y can do a piece of work in‘a days and‘b’days respectively, then working together:

Time to complete the work = (a b)/ (a + b)

In one day, they will finish= (a + b)/ (a b)

n By: Swati Mishra