Question

A student obtained the following marks in the first three exams of a subject: 2.8; 3.5 and 4.0. What grade must you get on the final exam to win the course with a 3.0 if each of the four grades has the same percentage?

A) 3.0
B) 2.0
C) 2.5
D) 2.75

Answer 1

The student needs to score 1.7 on the final exam to average a 3.0 across all four exams. Since that score isn't available among the options, the closest and sufficient choice is B) 2.0.

Step-by-step explanation:

The student wants to find out what grade they need on their final exam to achieve an average of 3.0 across all four exams, with all exams having the same weight. First, we calculate the sum of the three existing grades: 2.8 + 3.5 + 4.0 = 10.3. To average a 3.0 across four exams, the student needs a total of 3.0 × 4 = 12 points. Subtracting the already earned 10.3 points from the required 12 points gives us 1.7 points remaining for the final exam.

If the student needs 1.7 more points to reach a total of 12 points, and considering that the final exam is the fourth one, they must score a 1.7 on the final exam to achieve an overall average of 3.0. Therefore, amongst the options given, option B) 2.0 is the closest score the student can actually achieve on the last exam to ensure the overall average desired. In reality, the student would need to score slightly below a 2.0, but since that isn't an option, 2.0 is the lowest available score that will still allow the student to achieve their target average.