If x4y5z is exactly divisible by 9, then the least value of (x + y + z

1.	If x4y5z is exactly divisible by 9, then the least value of (x + y + z) is A. 3 B. 6 C. 9 D. 0
Answer» We know that if sum of digits of a number is divisible by 9, then the number is divisible by 9. Here, x + 4 + y + 5 + z = multiple of 9 x + y + z + 9 = 0, 9, 18, …. Hence, x + y + z + 18 = 18 But x + y + z cannot be 0 because then x, y and z will have to be 0.Since x is the first digit, it cannot be 0.∴ x + y + z + 18 = 27 x + y + z = 9 ∴ the least value of (x + y) is 9

If x4y5z is exactly divisible by 9, then the least value of (x + y + z) is A. 3 B. 6 C. 9 D. 0

Answer»

We know that if sum of digits of a number is divisible by 9, then the number is divisible by 9.

Here,

x + 4 + y + 5 + z = multiple of 9

x + y + z + 9 = 0, 9, 18, ….

Hence,

x + y + z + 18 = 18

But x + y + z cannot be 0 because then x, y and z will have to be 0.Since x is the first digit, it cannot be 0.∴ x + y + z + 18 = 27

x + y + z = 9

∴ the least value of (x + y) is 9