Variant 9.3.1. Natural numbers $a$ and $b$ are such that $a$ is divisible by $b+1$ and 43 is divisible by $a+b$.

(a) (1 point) Indicate any possible value of $a$.

(b) (3 points) What can $b$ be? Indicate all possible options.
Answer: (a) any of the numbers $22,33,40,42$. (b) $1,3,10,21$.