give the divisibility test for 3,4 and 9.
Answers
Answer:
divisiblity of 3 :- a number is divisivle by 3 when the sum of. the all digits of the number is divided by 3
divisibility of 4 :- a number is divisible by 4 when the last two digits of the number is divisible by 4
divisibility of 9 :- a number is divisible by 9 when this number is divisible by 3
Divisibility rule for 3
Divisibility rule for 3 states that a number is completely divisible by 3 if the sum of its digits is divisible by 3.
Consider a number, 308. To check whether 308 is divisible by 3 or not, take sum of the digits (i.e. 3+0+8= 11). Now check whether the sum is divisible by 3 or not. If the sum is a multiple of 3, then the original number is also divisible by 3. Here, since 11 is not divisible by 3, 308 is also not divisible by 3.
Divisibility rule of 4:
If the last two digits of a number are divisible by 4, then that number is a multiple of 4 and is divisible by 4 completely.
Example: Take the number 2308. Consider the last two digits i.e. 08. As 08 is divisible by 4, the original number 2308 is also divisible by 4.
Divisibility rule of 9:
The rule for divisibility by 9 is similar to divisibility rule for 3. That is, if the sum of digits of the number is divisible by 9, then the number itself is divisible by 9.
Example: Consider 78532, as the sum of its digits (7+8+5+3+2) is 25, which is not divisible by 9, hence 78532 is not divisible by 9.