- Write a program that prompts the user to enter a number and then prints the sum of all odd numbers from 1 to that number. -- The program should use a function to read the number and a function to ...

Given an array of integers arr, return the number of sub-arrays with an odd sum. A sub-array is a contiguous part of the array. The solution uses a prefix sum approach to efficiently count the number ...

On average, there are as many prime numbers for which the sum of decimal digits is even as prime numbers for which it is odd. This hypothesis, first made in 1968, has recently been proven by ...

A mathematical proof is a sequence of statements that follow on logically from each other that shows that something is always true. Using letters to stand for numbers means that we can make statements ...

A mathematical proof is a sequence of statements that follow on logically from each other that shows that something is always true. Using letters to stand for numbers means that we can make statements ...