Question

Check the numbers which are not divisible by 4?
\[
  (a){\text{ 3200}} \\
  (b){\text{ 4120}} \\
  (c){\text{ 3113}} \\
  (d){\text{ 9,812}} \\
 \]

Answer 1

Hint: Check for the last two digits for every number, if these last two digits are divisible by 4 then the entire number will be divisible by 4.

Complete step-by-step answer:

According to divisibility rule of 4 if the number formed by the last two digits in a number is divisible by 4 then the original number is divisible by 4
So check the options one by one
$\left( A \right)$ 3,200
As the last two digits are zero which is divisible by 4 hence the number is divisible by 4.
$\left( B \right)$ 4,120
As the last two digits are 20 which is divisible by 4 hence the number is divisible by 4.
$\left( C \right)$ 3,133
As the last two digits are 33 which is not divisible by 4 hence the number is not divisible by 4.
$\left( D \right)$ 9,812
As the last two digits are 12 which is divisible by 4 hence the number is divisible by 4.
So amongst the following numbers only 3,133 is the number which is not divisible by 4.
Hence option (C) is correct.

Note: There are certain tricks with which we can check for divisibility of number by some certain number, some of them are if the sum of all the digits of a number is divisible by 3 then the entire number is divisible by 3, if the last digit is divisible by 2 then the entire number is divisible by 2. If there lies 5 or 0 in the last of any number then the number is divisible by 5. If the number contains 0 in last then the number is divisible by 10. These tricks are very handy to save time.