In a class, students strength has been increased from 20 to 30. What percent of strength is increased ?

The percentage of strength that would have been increased is 10 because if you count from 20 to 30 that’s 10

The question is kind of confusing. if it's asking how many variations of answers can you give. then do 4^5 for your answer.this would be something like the first question could be a and the 2nd c or first b next c etc. if you can, ask the teacher for a better confirmation of what it's asking. if i'm assuming correctly what it's asking, it's 625 different variations.