There are 72 questions on a college entrance examination. One point is awarded for each correct answer, and one third of a one third of a point is deducted for each incorrect answer. How many questions does Tami need to answer correctly in order to score at least 60 points on the test? Assume that she answers every question.

Question

There are 72 questions on a college entrance examination.  One point is awarded for each correct​ answer, and one third of a one third of a point is deducted for each incorrect answer. How many questions does Tami need to answer correctly in order to score at least 60 points on the​ test? Assume that she answers every question.

Reiny · Answer

"one third of a one third of a point is deducted"
- why not just say say: " 1/9 of a point is deducted for an incorrecte answer" ??

number correct --- x
number incorrect --- 72-x

x - (1/9)(72-x) ≥ 60

x - 8 + (1/9)x ≥ 60
(10/9)x ≥ 68
x ≥ 61.2

So Tami must answer at least 62 correctly.

check:
with 61 correct:
score = 61 - (1/9)(11) = 59.78
with 62 correct
score = 62 - (1/9)(10) = 60.89 which is ≥ 60

Rebel · Answer

it is incorrect, can u please help me see why?

Steve · Answer

probably because the 1/3 of 1/3 is a typo.

If you discount the stuttering, you have

x - (1/3)(72-x) ≥ 60

Solve that and see what you get. If it works, next time check the solution and see whether it interprets your problem correctly, instead of just blindly accepting the answer.