Question

If 31z5 is a multiple of 3,where z is a digit find the value of z.

Answer 1

31z5 is a multiple of 3.then 3+1+5=9 then z= 0 then it is divisible by 3 so answer is 3105 or we have another answer that is z= 3,6,9 when we take these there values one by one all are divisible by 3 then also it is a multiple of three

Answer 2

Given:

Value = 31zp

Multiple = 3

To Find:

Value of Z.

Solution:

Since 31z5 is a multiple of three, thus the sum of the digits must also be a multiple of 3.

Therefore,

= 3 + 1 + z + 5

= 9 + z.

Thus, 9+z is a multiple of 3

Now, since z is a single digit, it can value anywhere from 0 - 9.

Thus, the possible values of z will be,

9 + 0 = 9

9 + 3 = 12

9 + 6 = 15

9 + 9 = 18

Answer: There can be four possible values of z which are 0,3,6 or 9