UPSC ISS Interview: Marks, Duration and What the Board Actually Tests

UPSC ISS interview explained with marks duration and board structure

The UPSC ISS interview, officially called the Personality Test, carries 200 marks out of the total 1200 marks of the Indian Statistical Service Examination. It usually lasts 20 to 30 minutes before a board of a chairperson and three to four members. Among recommended candidates of the last four available cycles, interview scores ranged roughly … Read more

RBI Monetary Policy June 2026: Repo Rate, Growth, Inflation

rbi-monetary-policy-june-2026-upsc-iss

Monetary policy questions look intimidating until you notice something. The Reserve Bank does only three things in every review: it sets a rate, it declares a stance, and it publishes forecasts. Once you learn to read those three things, every policy review in your life takes ten minutes to understand. The June 2026 review is … Read more

RBI Grade B DSIM Preparation 2027: The Complete Roadmap for Serious Aspirants

RBI DSIM preparation roadmap banner by StatChakravyuh with a golden bell curve on a navy data background

The RBI Grade B DSIM exam selects officers for the Department of Statistics and Information Management of the Reserve Bank of India through three stages: an objective Statistics paper, a descriptive round with Statistics and English, and an interview of 75 marks. The smartest route for RBI DSIM preparation in 2027 is a concept first … Read more

WPI New Base Year 2022-23 and India’s New PPI Explained

wpi-base-year-2022-23-producer-price-index-india

If you are preparing for the Indian Statistical Service, stop and read this one twice. Most current affairs topics are shared with every other examination in the country. This one is yours. It sits inside your General Studies paper, inside Official Statistics for Statistics Paper II, inside Index Numbers for Statistics Paper III, and it … Read more

Rakhigarhi Skeleton Study 2026: Key Facts for UPSC ISS GS

rakhigarhi-skeleton-study-upsc-iss

A student in our community wrote last month with a familiar complaint. She had studied the Indus Valley Civilization three times, could list Mohenjo daro, Harappa, Dholavira and Lothal without pausing, and still froze when a mock test asked what the Rakhigarhi excavations had added to our understanding of Harappan society. She knew the sites. … Read more

Part 16: Inverse Interpolation for UPSC ISS: Lagrange’s Swap and the Iterative Method

Inverse Interpolation for UPSC ISS

Welcome to Part 16, the final part of Module 4, updated for the UPSC ISS 2026 to 2027 cycle. So far the problem was always the same: given the arguments xx and their entries yy, predict a missing yy. That is direct interpolation. Today the examiner flips the script: given a value of yy, find … Read more

Part 15: Lagrange Interpolation Formula for UPSC ISS: The Table Free Interpolator

Lagrange Interpolation Formula for UPSC ISS

Welcome back to Part 15 of Module 4, updated for the UPSC ISS 2026 to 2027 cycle. In Part 14 we met Newton’s Divided Difference formula. Powerful, but it still needs a table. Today we go table free with the formula the syllabus names as “Lagrange’s formula for unequal intervals”: Lagrange’s Interpolation Formula, the examiner’s … Read more

Part 14: Newton’s Divided Difference Formula for UPSC ISS: The Universal Interpolator

Newton Divided Difference Formula for UPSC ISS

Welcome back to Part 14 of Module 4, updated for the UPSC ISS 2026 to 2027 cycle. In Part 13 we defined divided differences and discovered their symmetry. But a single difference is not a prediction. To actually build a polynomial and estimate a missing value from scattered data, we need the most versatile weapon … Read more