IBPS RRB IT Officer cheat sheet

SDLC phases in order: requirement analysis, feasibility study, design, coding, testing, deployment, maintenance; maintenance consumes the largest share of lifecycle cost.

Normalization: 1NF removes repeating groups; 2NF removes partial dependency on a composite key; 3NF removes transitive dependency; BCNF requires every determinant to be a candidate key.

ACID: Atomicity (all-or-nothing), Consistency (valid state transitions), Isolation (concurrent transactions do not interfere), Durability (committed data survives failure).

OSI seven layers bottom-up: Physical, Data Link, Network, Transport, Session, Presentation, Application; TCP/IP collapses these to Link, Internet, Transport, Application.

TCP is connection-oriented with 3-way handshake (SYN, SYN-ACK, ACK) and guarantees ordered delivery; UDP is connectionless, header 8 bytes, used for DNS, DHCP, streaming.

Symmetric ciphers (AES, DES) use one shared key and are fast; asymmetric ciphers (RSA, ECC) use public/private key pairs and are used for key exchange and digital signatures.

SQL joins: INNER returns matching rows only; LEFT/RIGHT retain all rows of one side with NULLs; FULL retains both; CROSS produces Cartesian product.

Index structures: B-tree for range queries, hash index for equality lookups; indexes speed reads but add write cost and storage.

Thread states: new, runnable, running, blocked/waiting, terminated; a deadlock needs mutual exclusion, hold-and-wait, no preemption, and circular wait simultaneously.

Alphabet positions: A=1 … Z=26; reverse position = 27 − forward position (A=26, Z=1). EJOTY mnemonic gives E=5, J=10, O=15, T=20, Y=25.

Blood relations: draw a tree; vertical line = parent-child generation, horizontal line = spouse or sibling; never assume gender from a name alone.

Direction sense: N, E, S, W at 90°; use Pythagoras for shortest distance, e.g. 3 km north then 4 km east gives 5 km displacement.

Syllogism: 'All A are B' + 'All B are C' implies 'All A are C'; 'Some A are B' cannot yield a universal conclusion; two particular premises give no definite conclusion.

Seating: for a circle, facing centre means left is clockwise; facing outward means left is anticlockwise.

Coding-decoding: check letter shift, reversal, positional arithmetic, and vowel/consonant substitution before assuming a single rule.

Series: alternate-series and difference-of-difference patterns; for squares/cubes check n²±k and n³±k before arithmetic progression.

Inequality: 'A > B ≥ C' implies A > C; combining '>' with '<' in the same chain gives no definite relation between the extremes.

Percentage change: increase = (new − old)/old × 100; successive changes of a% and b% give net a + b + ab/100.

Simple interest SI = PRT/100; compound interest CI = P(1 + R/100)^T − P; for 2 years CI − SI = P(R/100)².

Profit and loss: profit% = (SP − CP)/CP × 100; discount is always calculated on marked price, profit on cost price.

Speed: distance = speed × time; km/h to m/s multiply by 5/18; for equal distances at speeds x and y, average speed = 2xy/(x + y).

Time and work: if A does a job in x days and B in y days, together they take xy/(x + y) days; efficiency is inversely proportional to time.

Pipes and cisterns: inlet rates add, outlet rates subtract; a leak that empties in y hours is a negative rate of 1/y.

Boats: downstream speed = boat + stream, upstream = boat − stream; boat speed = (down + up)/2, stream = (down − up)/2.

Simple interest yields equal yearly increments; compound interest increments grow each year, so CI exceeds SI from year two onward.

Ratio and mixture: alligation rule gives ratio of quantities = (mean − cheaper) : (dearer − mean).

Subject-verb agreement: singular subject takes singular verb; 'one of the + plural noun' takes a singular verb (One of the boys is here).

Articles: 'a' before consonant sounds, 'an' before vowel sounds; 'the' for unique or previously specified nouns.

Tenses: present perfect (has/have + past participle) for past actions with present relevance; past perfect for the earlier of two past events.

Prepositions of time: in (months, years, seasons), on (days, dates), at (clock times); 'since' with a point of time, 'for' with a duration.

Active to passive: object becomes subject, verb becomes be + past participle, agent introduced by 'by'.

Common confusables: affect (verb) vs effect (noun); principal (head/main) vs principle (rule); stationary (still) vs stationery (writing material).

Error spotting: check subject-verb agreement, pronoun antecedent, tense consistency, article use, and preposition collocation in that order.

Hindi grammar: संधि combines two sounds (स्वर संधि, व्यंजन संधि, विसर्ग संधि); समास joins two words into a compound, e.g. द्वंद्व, तत्पुरुष, बहुव्रीहि.

Hindi synonyms/antonyms hinge on तत्सम (Sanskrit-derived) vs तद्भव (evolved) forms and on common pairs such as उत्कर्ष–अपकर्ष.

RBI was established on 1 April 1935 under the RBI Act, 1934, and nationalised in 1949; it is India's central bank and monetary authority.

Monetary policy tools: repo rate (RBI lends to banks), reverse repo (RBI absorbs liquidity), CRR (cash reserve with RBI), SLR (liquid assets held by banks), OMO, and MSF.

Banking Regulation Act, 1949 governs commercial banks; cooperative banks are also covered by it, with dual regulation by RBI and state registrars.

Types of banks: scheduled (listed in the Second Schedule of RBI Act), public sector, private, foreign, regional rural banks (RRBs), and small finance/payments banks.

RRBs were set up from 2 October 1975 under the RRB Act, 1976; shareholding is 50% central government, 15% state government, 35% sponsor bank.

NPA classification: substandard (up to 12 months), doubtful (over 12 months), loss asset; loans overdue over 90 days are NPAs.

Priority sector lending target is 40% of adjusted net bank credit for commercial banks, with sub-targets for agriculture, MSME, and weaker sections.

Payment systems: RTGS for high-value real-time settlement (minimum ₹2 lakh), NEFT for batch settlement, IMPS and UPI for instant retail transfers.

Instruments: cheque, demand draft, bill of exchange, promissory note; a cheque is drawn on a bank and payable on demand.

Memory hierarchy by speed: registers > cache > RAM > SSD > HDD > optical; ROM is non-volatile, RAM is volatile.

1 KB = 1024 bytes, 1 MB = 1024 KB, 1 GB = 1024 MB, 1 TB = 1024 GB; a nibble is 4 bits, a byte is 8 bits.

Shortcuts: Ctrl+C copy, Ctrl+X cut, Ctrl+V paste, Ctrl+Z undo, Ctrl+Y redo, Ctrl+A select all, Ctrl+S save, Ctrl+P print, Alt+F4 close window.

MS Excel: $A$1 absolute reference, A$1 mixed row-absolute, $A1 mixed column-absolute; SUM, AVERAGE, COUNT, IF, VLOOKUP are core functions.

IP address: IPv4 is 32-bit dotted decimal, IPv6 is 128-bit hexadecimal; private ranges are 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16.

Common ports: HTTP 80, HTTPS 443, FTP 21, SSH 22, SMTP 25, DNS 53, Telnet 23.

Malware types: virus attaches to files, worm self-replicates over networks, trojan hides in legitimate software, ransomware encrypts data for ransom.

Generations: first (vacuum tubes), second (transistors), third (integrated circuits), fourth (microprocessors), fifth (AI and parallel processing).

File extensions: .docx Word, .xlsx Excel, .pptx PowerPoint, .pdf portable document, .exe executable, .jpg image, .mp3 audio.

Puzzle approach: fix the most constrained clue first, then eliminate; for floor/linear arrangements mark fixed positions before relative ones.

Alphanumeric series questions test position from left/right and classification (digit, vowel, consonant, symbol) rather than arithmetic.

Statement-assumption: an assumption is unstated but necessary for the statement; reject restatements and far-fetched possibilities.

Cause-effect: a valid cause must precede the effect in time and be sufficient to explain it; coincidence is not causation.

Data sufficiency: decide whether the data is sufficient, never compute the final answer; each statement is tested alone first, then together.

Input-output: track the transformation step by step (usually sorting or shifting) and verify the rule against the given steps.

Analogy and classification: identify the relation type (part-whole, worker-tool, cause-effect) before selecting the matching pair.