Question 82
Positive integer $b$ is obtained by reordering the digits in a positive integer $a$. Which of the following claims are definitely true?
a) The sums of the digits of numbers $2a$ and $2b$ are equal.
b) The sums of the digits of numbers $3a$ and $3b$ are equal.
c) The sums of the digits of numbers $5a$ and $5b$ are equal.
a) The sums of the digits of numbers $2a$ and $2b$ are equal.
b) The sums of the digits of numbers $3a$ and $3b$ are equal.
c) The sums of the digits of numbers $5a$ and $5b$ are equal.