Why Speed Matters More Than Knowledge
In SSC CGL, you get 36 seconds per question. In IBPS PO Prelims, 36 seconds. Most aspirants know the concepts but run out of time. These shortcuts are not tricks — they are efficient methods that top scorers use.
1. Percentage → Fraction Conversion
Memorize these: 10% = 1/10, 12.5% = 1/8, 16.67% = 1/6, 20% = 1/5, 25% = 1/4, 33.33% = 1/3, 50% = 1/2. Example: 37.5% of 240 = 3/8 × 240 = 90. Done in 3 seconds instead of 15.
2. Successive Discount Formula
Two discounts of a% and b% = (a + b - ab/100)%. Example: 20% and 10% discount = 20 + 10 - 200/100 = 28%. No need to calculate step by step.
3. Profit/Loss on Marked Price
If markup is M% and discount is D%, then Profit% = M - D - (M×D)/100. Example: 40% markup, 20% discount = 40 - 20 - 800/100 = 12% profit.
4. Time & Work — LCM Method
A does a job in 12 days, B in 15 days. LCM(12,15) = 60 units. A = 5 units/day, B = 4 units/day. Together = 9 units/day. Time = 60/9 = 6.67 days. Faster than fraction method.
5. Speed-Distance-Time — Ratio Trick
If speed increases by x/y times, time becomes y/x times (inverse ratio). Example: Speed doubles (2/1), time halves (1/2). No calculation needed.
6. Average — Deviation Method
For numbers close to each other, pick an assumed average. Calculate deviations. Average = assumed + (sum of deviations / count). Much faster for DI sets.
7. Number Series — Difference Method
Always calculate first differences, then second differences. If second differences are constant, it is a quadratic series. If first differences are constant, it is linear. This works for 80% of series questions.
Practice These Daily
Knowing shortcuts is useless without practice. Solve 20 Quant questions daily with a timer. After 30 days, these shortcuts become automatic and your speed doubles.