Why Arithmetic Decides the Food SI Cutoff
In the WBPSC Food Sub-Inspector examination, 13.3+ lakh candidates compete for fewer than 500 vacancies. In General Studies (50 Marks), even the most prepared aspirants rarely cross 38–40 marks due to subjective current affairs and unpredictable static GK.
However, the Arithmetic section (50 Marks) is 100% deterministic. If your calculation technique is sharp, scoring 45 to 48 out of 50 is realistic and essential to clear the 80+ cutoff benchmark.
50-Mark Topic Weightage Distribution
Based on the official previous year question papers (2014, 2019, and recent shifts):
| Topic (বাংলা বিষয়) | Typical Questions | Marks | Difficulty Level |
|---|---|---|---|
| Simplification & Fractions (সরলীকরণ ও ভগ্নাংশ) | 6 - 8 | 6 - 8 | Easy - Moderate |
| LCM & HCF (ল.সা.গু ও গ.সা.গু) | 4 - 5 | 4 - 5 | Easy |
| Percentage & Profit/Loss (শতকরা ও লাভ-ক্ষতি) | 8 - 10 | 8 - 10 | Moderate |
| Ratio, Proportion & Partnership (অনুপাত ও অংশীদারি কারবার) | 6 - 8 | 6 - 8 | Easy - Moderate |
| Time, Work & Cistern (সময়, কার্য ও নল-চৌবাচ্চা) | 5 - 6 | 5 - 6 | Moderate |
| Speed, Distance, Train & Boat (গতিবেগ, ট্রেন ও নৌকা) | 6 - 7 | 6 - 7 | Moderate - Tricky |
| Average & Age Problems (গড় ও বয়সের অঙ্ক) | 4 - 5 | 4 - 5 | Easy |
| Simple & Compound Interest (সরল ও চক্রবৃদ্ধি সুদ) | 4 - 5 | 4 - 5 | Moderate |
Key Formula Shortcuts You Must Memorize
1. Successive Percentage Change (কার্যকরী শতকরা পরিবর্তন)
When an item's price increases by $a%$ and consumption decreases by $b%$, net expenditure change: $$\text{Net Change} = a - b - \frac{a \times b}{100}$$
2. Relative Speed for Train Crossing
Two trains moving in the same direction with speeds $u$ and $v$ ($u > v$): $$\text{Relative Speed} = u - v$$
Two trains moving in opposite directions: $$\text{Relative Speed} = u + v$$
Conversion factor: $\text{km/h} \to \text{m/s}$ is multiplied by $\frac{5}{18}$.
3. Downstream & Upstream Boat Speed
Still water speed $u = \frac{\text{Downstream} + \text{Upstream}}{2}$
Current speed $v = \frac{\text{Downstream} - \text{Upstream}}{2}$
Daily 90-Minute Drill Routine for Food SI
First 20 Minutes: Rapid mental math (Multiplication tables up to 30, squares up to 40, cubes up to 20, fraction-to-percentage conversion like $1/7 = 14.28%$).
Next 40 Minutes: Solve 30 topic-wise problems from WBBSE Ganit Prakash Class 9 & 10 textbooks.
Last 30 Minutes: Solve 1 full mixed 50-question mock test under a strict 45-minute countdown clock.