50 Keys To CAT

Arithmetic, Algebra, Geometry and Modern Mathematics
A collection of 50 very important formulae for Quantitative Ability Section of CAT from the pioneers of online CAT training

▪ EASY ▪ EFFECTIVE ▪ PERSONALISED

1. Averages

2. Mean

For two numbers a and b,

3. Percentage Change

For two successive changes of a% and b%,

4. Interest

Amount = Principal + Interest © 2008 Enabilon Learning Pvt. Ltd. All rights reserved. 1

5. Population Formula

[Here, P = Original population, P’ = population after n years, r% = rate of annual change]

6. Depreciation Formula

[Here, P = original value, P’ = final value after n years, r% = rate of annual depreciation]

7. Growth
Absolute Growth = Final Value – Initial Value

[Here, S. A. G. R. = Simple Annual Growth Rate, A. A. G. R. = Average Annual Growth Rate and C. A. G. R. = Compound Annual Growth Rate]

8. Profit and Loss
Profit = SP − CP Loss = CP − SP

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9. False Weights
If an item is claimed to be sold at cost price, using false weights, then the overall percentage profit is given by

10.

Discount

Discount = Marked Price − Selling Price

Buy x and Get y Free If articles worth Rs. x are bought and articles worth Rs. y are obtained free along with x articles, then the discount is equal to y and discount percentage is given by

Successive Discounts When a discount of a% is followed by another discount of b%, then

11.

Ratios

If a : b = c : d, then a : b = c : d = (a + c) : (b + d) If a < b, then for a positive quantity x,

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If a > b, then for a positive quantity x,

12.

Proportions

13.

Successive Replacement

Where x is the original quantity, y is the quantity that is replaced and n is the number of times the