Question

If 31z5 is a multiple of 3 , where z is a digit , what might br the value of z​

Answer 1

Answer:

The values of z might be 1 , 4 or 7 .

Step-by-step explanation:

Divisibility Test :

The divisibility test for a number to be divisible by 3 is the sum of digits constituting number Sould be a multiple of 3

3z5 is divisible by 3

Hence ( 3 + 5 + z ) i.e. ( z + 8 ) is a multiple of 3 .

For z = 1 , sum is 9 .

Similarly for z = 4 , z = 7 the sum will be divisible by 3 .

THANKS!!!

Answer 2

Answer:

$1$

Step-by-step explanation:

As mentioned in the question that 3z5 is a multiple of 3, it means that 3 divide 3z5 completely.

For the divisibility of any number by 3 it is necessary to have the sum of the number divisible by 3.

For Example -

3432 = 3 + 4 + 3 + 2 = 12

here 12 is divisible by 3 so, this 3432 is also completely divisible by 3

Now,

According to question,

3z5

here we need to find z

3 + z + 5 = 9

8 + z = 9

z = 1

Hence,

The Number is 315 and the value of z is 1

NOTE - The value of z vary , here I took the smallest number that is divisible by 9

If u took the sum 12 then the value of z is

3 + z + 5 = 12

z = 4

The answer is based on that what sum you taken.