Answer:
The local newspaper has 250 readers in total
Step-by-step explanation:
Given that
Letter to the editor = 10
Also it is given that 10 is the 4% of total readers of the newspaper.
Let x be the number of readers of the newspaper
It can be written as:

Converting the percentage into decimal

The newspaper has 250 readers.
Hence,
The local newspaper has 250 readers in total
The greatest 3 digit number divisible by the 8, the 10, and the 12 is 960. The simplest way of finding the number is to multiply all the divisible factor which is the 8, the 10, and the 12 that results in 960 (8*10*12). If this multiply operation results in more than 3 digit number, therefore we must analyze the factor of the result and eliminate it.
280........................................