CAT (QA) PYQs

The sum of all four-digit numbers that can be formed with the distinct non-zero digits $a, b, c,$ and $d$, with each digit appearing exactly once in every number, is $153310 + n$, where $n$ is a single digit natural number. Then, the value of $(a + b + c + d + n)$ is

How many integers in the set $(100,101,102, \ldots, 999)$ have at least one digit repeated?

Let $AB, CD, EF, GH,$ and $JK$ be five diameters of a circle with center at $O$. In how many ways can three points be chosen out of $A, B, C, D, E, F, G, H, J, K,$ and $O$ so as to form a triangle?