# Divisibility, HCF & LCM Tricks and Formulas

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## Divisibility Tests

- A number is divisible by 2, if its unit՚s place digit is 0,2, 4, or 8
- A number is divisible by 3, if the sum of its digits is divisible by 3
- A number is divisible by 4, if the number for med by its last two digits is divisible by 4
- A number is divisible by 8, if the number formed by its last three digits is divisible by 8
- A number is divisible by 9, if the sum of its digits is divisible by 9
- A number is divisible by 11, if, starting from the RHS, (Sum of its digits at the odd place) – (Sum of its digits at even place) is equal to 0 or 11x

## HCF and LCM

## Application of H. C. F

The greatest natural number that will divide *x*, *y* and *z* leaving remainders *r*1, *r*2 and *r*3, respectively, is the

## Application of L. C. M

The smallest natural number that is divisible by *x*, *y* and *z* leaving the same remainder *r* in each case is the