As per the problem
The chemicals in my swimming pool use a ratio of 5 tablets of chlorine for every 14 days.
we have been asked to find
Which ratio shows the number of chlorine tablets needed for 42 days?
Since for each 14 days the number of tablets required is 5
So if you multiply the number of days by some number then, we will have to multiply the number of tablets required by the same number.
So When number of days
Then the number of tablets required for 42 days is