IBPS Clerk Formula Sheet
Ten formulas, what each one is for, and a worked example.
IBPS Clerk maths is short arithmetic under time pressure. Alongside simplification and number series, Prelims sets a few word problems, and Mains adds more of them plus DI.
These ten formulas cover the word-problem topics, with a worked time-and-work example.
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The 10 Formulas
1
Formula
Percentage change
Expression
(New − Old) ÷ Old × 100
Use it for
Growth and fall in values, and the base of most DI questions.
2
Formula
Profit %
Expression
(SP − CP) ÷ CP × 100
Use it for
Profit or loss on cost price.
3
Formula
Simple interest
Expression
SI = P × R × T ÷ 100
Use it for
Interest that isn't added back to the principal.
4
Formula
Compound interest
Expression
A = P × (1 + R/100)ᵀ; CI = A − P
Use it for
Interest compounded once a year.
5
Formula
Time and work (two people)
Expression
Days together = (a × b) ÷ (a + b)
Use it for
When A alone takes a days and B alone takes b days.
6
Formula
Pipes and cisterns
Expression
Net fill per hour = 1/a − 1/b
Use it for
One pipe filling (a hours) while another empties (b hours).
7
Formula
Speed, distance, time
Expression
Distance = Speed × Time; km/h × 5/18 = m/s
Use it for
Trains, journeys and unit conversions.
8
Formula
Train crossing a platform
Expression
Time = (Train length + Platform length) ÷ Speed
Use it for
A train crossing a pole uses its own length only.
9
Formula
Problems on ages
Expression
Write both ages now as x and y, then shift both by the same number of years
Use it for
Age-ratio questions: both ages change by the same amount.
10
Formula
Dividing in a ratio
Expression
Share of A = Total × a ÷ (a + b)
Use it for
Splitting an amount, profit or quantity in a ratio.
| # | Formula | Expression | Use it for |
|---|---|---|---|
| 1 | Percentage change | (New − Old) ÷ Old × 100 | Growth and fall in values, and the base of most DI questions. |
| 2 | Profit % | (SP − CP) ÷ CP × 100 | Profit or loss on cost price. |
| 3 | Simple interest | SI = P × R × T ÷ 100 | Interest that isn't added back to the principal. |
| 4 | Compound interest | A = P × (1 + R/100)ᵀ; CI = A − P | Interest compounded once a year. |
| 5 | Time and work (two people) | Days together = (a × b) ÷ (a + b) | When A alone takes a days and B alone takes b days. |
| 6 | Pipes and cisterns | Net fill per hour = 1/a − 1/b | One pipe filling (a hours) while another empties (b hours). |
| 7 | Speed, distance, time | Distance = Speed × Time; km/h × 5/18 = m/s | Trains, journeys and unit conversions. |
| 8 | Train crossing a platform | Time = (Train length + Platform length) ÷ Speed | A train crossing a pole uses its own length only. |
| 9 | Problems on ages | Write both ages now as x and y, then shift both by the same number of years | Age-ratio questions: both ages change by the same amount. |
| 10 | Dividing in a ratio | Share of A = Total × a ÷ (a + b) | Splitting an amount, profit or quantity in a ratio. |
Worked Example: Time and Work
A can finish a job in 12 days and B in 18 days. How long do they take together?
- 1
Apply the formula
(12 × 18) ÷ (12 + 18) = 216 ÷ 30.
- 2
Answer
7.2 days.
- 3
Check with work per day
1/12 + 1/18 = 5/36 of the job a day, so 36 ÷ 5 = 7.2 days.
Real questions from these exact topics. No signup.
Number Series Have No Formula
Number series and simplification take a big share of Prelims but rely on pattern spotting and mental arithmetic. Practise them daily alongside these formulas.
FAQs
How many maths questions are in IBPS Clerk Prelims?expand_more
35 Numerical Ability questions.
Does IBPS Clerk have DI?expand_more
Yes, mainly in Mains. Prelims may have one short set.
Is IBPS Clerk maths the same as SBI Clerk?expand_more
The topics overlap heavily, but question styles and difficulty vary each year.
Next steps
Take a full IBPS Clerk mock testThe whole syllabus, timed and scored, in one sitting.