All answers must contain the string 2023:
1. What is the smallest number written exactly with 7 digits?
2. What is the smallest integer using 11 digits i.e. all digits 0 to 9 and an extra digit 2?
3. Write down the smallest square s.t. each digit is present at least once.
4. Evaluate the quadruplet {a,b,c,d} of distinct non-negative integers, s.t. a*b+c+d=2023 and abcd is minimal.

The 1st solver is kindly requested to post at least 2 answers out of the set of four.

(In reply to re: solutions by Ady TZIDON)

For 4 I had thought that abcd meant the concatenation, not the product.

Edited on December 30, 2022, 7:39 am

Posted by Charlie on 2022-12-30 07:38:21