Here is Postal Assistant / Sorting Assistant Syllabus with Exam Pattern detailed.
India Post conducts Postal assistant/ sorting assistant exam for recruiting candidates. Lakhs of candidates apply for this examination. The selection of candidates for recruitment will be done on basis of written test. So here is the Postal Assistant Syllabus - PA / SA Syllabus and Exam Pattern is provided after that.

Postal Assistant Syllabus - India Post PA / SA Syllabus

This syllabus also apply for Sorting Assistant.
Here is a detailed Postal Assistant syllabus of each section.
1. General Knowledge section:
This section includes Basic concepts of Economy, History, Geography Indian Polity and General Science. Current Affairs based on last 6 months updates on appointments, summits, deaths, awards, Sports.
2. Mathematics section:
This section contains basics of basic maths which are process of finding squares, shortcuts, cubes, square roots, cube roots. Simplifications, , ratios and proportions,  approximations simple and compound interests, profit loss, time and distance ,percentages, averages, time and work, Mensuration, speed and distance etc.
3. Postal Assistant / Sorting Assistant syllabus of English Grammar section:
This section containing Basic English grammar questions. Basic English grammar consists of antonyms, adverbs, synonyms, prepositions, usage of verbs, tenses, singular and plural, direct and indirect speech, conjunctions etc.
4. Postal Assistant / Sorting Assistant syllabus of Reasoning & Mental Ability section:
Basic reasoning topics like directions, blood relations, basics of analogy, Cubes and dice problems, alpha numeric symbol tests, coding and decoding, comparisons (ranking test),Statement and assumptions, statement and conclusion, Calenders, series completion, venn diagrams , seating arrangement etc.
PA/SA Syllabus

Paper 2 – (Computer / Typing Test): Computer / Typing Test consist of two parts in which Typing Test will be of 15 minutes and Data Entry is of 15 minutes also. Your typing speed for typing Test should be 25 words per minute (in Hindi) and 30 words per minute (in English).

Postal Assistant / Sorting Assistant Exam Pattern:
The Postal Assistant / Sorting Assistant Exam consist of two papers.
Paper 1 is an Aptitude Test while Paper 2 is a Computer / Typing Test. The Postal Assistant / Sorting Assistant syllabus is given after exam pattern.
Paper one ( Aptitude Test ): Postal Assistant / Sorting Assistant exam consists of four sections. these sections are
1.       Mathematics
2.       General Knowledge
3.       Reasoning and Mental Ability
4.       English Grammar
Total no. of marks of this test is hundred marks. Each section contains twenty five questions and these questions are of twenty five marks. So 100 questions carry total 100 marks. Aptitude test will carry 100 marks.