I need simple app ideas that solve basic problems​

What characteristic of long period comets suggest they come directly from the oort cloud?

Why is it uncommon for users to perform searches directly in database tables? a.)users are discouraged from interacting directly with tables because they might confuse tables with spreadsheets. b.) users are discouraged from interacting directly with tables because this may result in unintended changes to source data. c.)users do not have the technical skills required to perform searches directly in database tables. d.)users do not have the permissions required to perform searches directly in database tables.

7. design a circuit with three inputs (x, y, and z) representing the bits in a binary number, and three outputs (a, b, and c) also representing bits in a binary number. when the input is 1, 2, or 3, the binary output should be one lesser than the input. when the input is 4, 5, or 6, the binary output should be one greater than the input. when the input is 0, the output is 0, and when the input is 7, the output is 7. show your truth table, all computations for simplification, and the final circuit.