Simplification & Approximation

GETTING STARTED

☛ BODMAS rule:

The long mathematical expressions are always solved using BODMAS rule.

It gives the sequence in which expressions are solved.

 B – Bracket

 O – Of

 D-Division

 M-Multiplication

 A-Addition

 S-Subtraction

 ☛ First the brackets are solved. Within brackets also there is an order to solve – (), then {} and then [ ].

☛  After brackets, Division operation is to be carried out followed by Multiplication.

☛ After multiplication, addition and subtraction are carried out.

Virnaculum:

     Some questions may have a bar over a few terms indicating that they are to be solved even before starting off with brackets

☛ Modulus of a number:

This expression always returns a non-negative value irrespective of the input.

Y= f (x) =|x|

Eg. Let x = 50

Y= |50| = 50

Let x = -50

Y = |-50| = 50

Approximation:

☛It helps in quickening the process of arriving at an answer. It is one of the most important topics to be continuously practiced for MCQ type exams.

☛ Approximation helps in eliminating incorrect answer choices quickly.

☛The best way to approximate is to reduce the numbers to its nearest integer which can be easily used for calculation. 

Let us consider an example:

A) 302

B) 502

C)202

D)102

Soln:

Approximating, we get,

 

Solving Further,

=(60 + 140 -230 +230)/2

=100

Of the given options, the alternatives are too apart the closest number is 102.

Therefore D is the right answer.