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Divisibility Rules
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We will talk about Divisibility Rules and take up questions based on the same.

Vishal Sharma
I am an engineer by education and teacher by choice.I have been training students for CAT exams for 16 years.I have worked with top brands l

Unacademy user
sir can we get ppt?
  1. Faculty : Vishal Sharma More than 16 years of experience in CAT training Trained 10000+ students till date


  2. Topic for Session Divisibility Rules


  3. 2 -Last digit divisible by 2 4 -Last 2 digit divisible by 4 8 -Last 3 digit divisible by 8 5 -Last digit divisible by 5 25 -Last 2 digit divisible by 25 125 -Last 3 digit divisible by 125 3- Sum of digits divisible by 3 . 9- Sum of digits divisible by 9


  4. Some more Rules Rule for 11 Let's say number is 'abcdefg' Eg: 1331 - (1+3) (1+3) 0 For other Numbers like 6: 2 and 3 12: 3 and4 88: 11 and 8 How I am making Rules


  5. Q) By using digits 0-9 once what greatest number divisible by 8 can be Rule We areformed? looking Greatest No Tor Co-Prime So last 3 digits, rearrange Factors 9876543210 but 8 Rule last 3 digit -8 we get 120 So, 9876543120


  6. Some interesting Rules If we add two digit number to its reverse ( 11) eg 28 +82-110 95+59- 154 1057+7501- 8558 . If we take difference of3 digit number & its reverse difference is divisible by 99 eg 791 - 197 594 The largest natural number which necessarily divides product of four consecutive natural number


  7. Let's learn one more concept When you divide 10 by 3; Q-3, R-1, Dividend-10 and Divisor So , Dividend - Divisor * Quotient Remainder So, 10 3*3+1 Q.) A number when divided by 136 leaves remainder 36.What is the remainder when same number is divided by 17? Sol) Let no be N, N 136k + 36 N/17 136k/17 36/17 Remainder from 36/17 2


  8. Working: Let's focus on div Let's Practice One last Question Q.) 3422213** No is div by 99. Find missing digits a)1,9 b)3,7 c)4,6 d)5,5 rule for 9 (17 +a+b) 9 Let's focus on rule for 11 (10+b) ~ (7 +a) - 3+b-a Only option (a) satisfies.


  9. Thank You