If 31P5 is a multiple of 3 then find the value of P, where P is a digi

1.	If 31P5 is a multiple of 3 then find the value of P, where P is a digit?
Answer» Given Number = 31P5 Sum of digits = 3 + 1 + P + 5 = 9 + P But 9 + P is a multiple of 3 so it is only possible if values of 9 + P are 9, 12, 15, 18, ….etc. If 9 + P = 9 then P = 0 If 9 + P = 12 then P = 3 If 9 + P = 15 then P = 6 If 9 + P = 18 then P = 9 If 9 + P = 21 then P = 12 But P is a digit so P ≠ 12 Therefore, values of P are 0, 3, 6 and 9

If 31P5 is a multiple of 3 then find the value of P, where P is a digit?

Answer»

Given Number = 31P5

Sum of digits = 3 + 1 + P + 5 = 9 + P

But 9 + P is a multiple of 3 so it is only possible if values of 9 + P are 9, 12, 15, 18, ….etc.

If 9 + P = 9 then P = 0

If 9 + P = 12 then P = 3

If 9 + P = 15 then P = 6

If 9 + P = 18 then P = 9

If 9 + P = 21 then P = 12

But P is a digit so P ≠ 12

Therefore, values of P are 0, 3, 6 and 9