Question

alice average mark for 4 science exams is 68%. Can alice score enough marks In a fifth exam so that her average Mark increases to 75% give reasons

Answer 1

it is impossible she gets a 75% because as far as we know she can only score a maximum of 100 and she needs a 103

Explanation:

We're going to assume that alice got a 68 on all 4 of her science exams

which means that so far we have
`(68+68+68+68)/(4)=68`

And we need to find out if she can get a 75 which means that we have the following

`(68+68+68+68+x)/(5)=75`

Solve for x

272+x=375

x= 103

Therefore (unless there is extra credit available in the exam) it is impossible she gets a 75% because as far as we know she can only score a maximum of 100