6. The numbers 100 and 90 were divided by the same number. In the first case, the remainder was 4, and in the other case, it was 18. By what number were they divided?
6. The sought divisor divides the numbers $96(100-4=96)$ and $72(90-18=72)$. This divisor will be common for the numbers 96 and 72. Since the remainders upon division are 4 and 18, the divisor is greater than 18. Such a number is 24, since the GCD $(96,72)=24$