If 3-digit number 89y is divisible by 9 then find the value of y?

1.	If 3-digit number 89y is divisible by 9 then find the value of y?
Answer» Given number is 89y ∴Sum of digits = 8 + 9 + y = 17 + y But 17 + y is divisible by 9, this is possible only number may be either 18, 27, 36…etc. But y is a digit . If 17 + y = 18, then y = 18 – 17 = 1 If 17 + y = 27, then y = 27 – 17 = 10 But y is a digit so y ≠ 10 therefore y = 1

Answer»

Given number is 89y

∴Sum of digits = 8 + 9 + y = 17 + y

But 17 + y is divisible by 9, this is possible only number may be either 18, 27, 36…etc. But y is a digit .

If 17 + y = 18, then y = 18 – 17 = 1

If 17 + y = 27, then y = 27 – 17 = 10

But y is a digit so y ≠ 10 therefore y = 1

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