Respuesta :
Answer:
He needs to get 1 right
Step-by-step explanation:
1/40 is equal to .025. This means the other 39/40 incorrect ones are worth .975(97.5%). If we multiply the .975 by the 15 percent of his overall grade, we get 14.625. When you subtract this from the overall grade, you get 70.075, which is just above a 70%.
For this case we have that the general qualification is 70, of it Evan has accumulated 84.7%. Making a rule of three:
70 ----------> 100%
x -------------> 84.7%
Where "x" represents the rating that Evan has accumulated:
[tex]x = \frac {84.7 * 70} {100}\\x = 59.29\\70-59.29 = 10.71[/tex]
Evan is missing 10.71 to get 70.
In percentage, we have to:
100% -84.7% = 15.3%
Now we have that the exam represents 15% of the grade, this is divided into 40 questions.
It is observed that Evan must correctly answer the 40 questions of the exam, so he would get 15%. Even so, it would lack a 0.3% note to reach 70.
Answer:
He must answer the 40 questions correctly.