Question

A survey was done to determine the effect of students changing answers while taking a​ multiple-choice test on which there is only one correct answer for each question. Some students erase their initial choice and replace it with another. It turned out that 51​% of the changes were from incorrect answers to correct and that 27​% were from correct to incorrect. What percent of changes were from incorrect to​ incorrect?

Answer 1

22%

Explanation:

In the event of changing a test answer there are three possible outcomes, which should add up to 100%: changing from incorrect to correct (51%), changing from correct to incorrect (27%) and changing from incorrect to incorrect (X). Therefore, the percent of changes from incorrect to​ incorrect was:

`100\% = 51\%+27\%+X\\X= 22\%`

22% of the changes were from incorrect to​ incorrect.