How to work out 13 out of 15
Divide the score by the total and multiply by 100: 13 ÷ 15 = 0.8667, and 0.8667 × 100 = 86.67%.
That means 2 answers were wrong, and each question was worth 6.67% of the total. One more correct answer (14/15) would be 93.33%.
Grading chart for 15 questions
| Wrong | Score | Percent | Grade |
|---|---|---|---|
| 0 | 15/15 | 100% | A+ |
| 1 | 14/15 | 93.3% | A |
| 2 | 13/15 | 86.7% | B |
| 3 | 12/15 | 80% | B− |
| 4 | 11/15 | 73.3% | C |
| 5 | 10/15 | 66.7% | D |
| 6 | 9/15 | 60% | D− |
| 7 | 8/15 | 53.3% | F |
| 8 | 7/15 | 46.7% | F |
| 9 | 6/15 | 40% | F |
| 10 | 5/15 | 33.3% | F |
| 11 | 4/15 | 26.7% | F |
| 12 | 3/15 | 20% | F |
| 13 | 2/15 | 13.3% | F |
| 14 | 1/15 | 6.7% | F |
| 15 | 0/15 | 0% | F |
Letter grades use the common US scale (A ≥ 93%, B ≥ 83%, C ≥ 73%, D ≥ 63%, with ± bands). Your school may use different cut-offs.