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.
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.
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
· For equilateral triangle
· For right angle triangle
Pythagoras theorem to calculate third side i.e. hypotenuse
h2=p2+b2, where p is perpendicular or height
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.
Perimeter= 4* side
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
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
· 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