Final answer:
To find the percentage of couples who disagree on a particular matter, divide the number of couples who disagree by the total number of couples and multiply by 100.
Step-by-step explanation:
To find the percentage of couples who disagree on a particular matter, we need to convert the ratio to a percentage. Since there are 7 couples out of 10 who disagree, we can calculate the percentage using the formula:
Percentage = (Number of couples who disagree / Total number of couples) * 100
Plugging in the values, we get:
Percentage = (7 / 10) * 100 = 70%
Therefore, 70% of couples disagree on the matter.