ব্যাংক জব নিয়োগ পরীক্ষা গণিত Number

Divisibility by 10

A number is divisible by 10 if the last digit is 0.

Example1: Check if 2570 is divisible by 10.
Last digit is 0. Hence 2570 is divisible by 10.

Example2: Check if 5462 is divisible by 10.

Last digit is not 0. Hence 5462 is not divisible by 10
Divisibility by 11

To find out if a number is divisible by 11, find the sum of the odd numbered digits and the sum of the even numbered digits.

Now substract the lower number obtained from the bigger number obtained.

If the number we get is 0 or divisible by 11, the original number is also divisible by 11.

Example1: Check if 85136 is divisible by 11.

8 + 1 + 6 = 15
5 + 3 = 8
15 – 8 = 7
7 is not divisible by 11. Hence 85136 is not divisible by 11.

Example2: Check if 2737152 is divisible by 11.
2 + 3 + 1 + 2 = 8
7 + 7 + 5 = 19
19 – 8 = 11
11 is divisible by 11. Hence 2737152 is also divisible by 11.

Example3: Check if 957 is divisible by 11.
9 + 7 = 16
5 = 5
16 – 5 = 11
11 is divisible by 11. Hence 957 is also divisible by 11.

Example4: Check if 9548 is divisible by 11.
9 + 4 = 13
5 + 8 = 13
13 – 13 = 0
We got the difference as 0. Hence 9548 is divisible by 11.
Divisibility by 12

A number is divisible by 12 if the number is divisible by both 3 and 4

Example1: Check if 720 is divisible by 12.
720 is divisible by 3 and 720 is also divisible by 4. (Check the divisibility rules of 3 and 4 to find out this)
Hence 720 is also divisible by 12

Example2: Check if 916 is divisible by 12.
916 is not divisible by 3 , though 916 is divisible by 4.(Check the divisibility rules of 3 and 4 to find out this)
Hence 916 is not divisible by 12

Example3: Check if 921 is divisible by 12.
921 is divisible by 3. But 921 is not divisible by 4.(Check the divisibility rules of 3 and 4 to find out this)
Hence 921 is not divisible by 12

Example4: Check if 827 is divisible by 12.
827 is not divisible by 3. 827 is also not divisible by 4.(Check the divisibility rules of 3 and 4 to find out this)
Hence 827 is not divisible by 12

Divisibility by 13

To find out if a number is divisible by 13, multiply the last digit by 4 and add it to the number formed by the remaining digits.
Repeat this process until we get at a smaller number whose divisibility we know.If this smaller number is divisible by 13, the original number is also divisible by 13.

Example1: Check if 349 is divisible by 13.
Given number = 349
34 + (9 × 4) = 34 + 36 = 70
70 is not divisible by 13. Hence 349 is not divisible by 349

Example2: Check if 572 is divisible by 13.
Given number = 572
57 + (2 × 4) = 57 + 8 = 65
65 is divisible by 13. Hence 572 is also divisible by 13

Example3: Check if 68172 is divisible by 13.
Given number = 68172
6817 + (2 × 4) = 6817 + 8 = 6825
682 + (5 × 4) = 682 + 20 = 702
70 + (2 × 4) = 70 + 8 = 78
78 is divisible by 13. Hence 68172 is also divisible by 13.

Example4: Check if 651 is divisible by 13.
Given number = 651
65 + (1 × 4) = 65 + 4 = 69
69 is not divisible by 13. Hence 651 is not divisible by 13

এই লেকচারের পরের পেইজে যেতে নিচের …. তে ক্লিক কর।