84% of 50 is 42. So if your test was graded out of 50 you would've gotten 42/50. If you multiply 50 by 2 (50x2), you have 100, so then you'd just divide the 84% by 2 so you'd get 42%
        
                    
             
        
        
        
Answer:
<h2>2.2</h2>
Step-by-step explanation:
Use the cosine law (look at the picture).
We have:


 → look at the second picture
 → look at the second picture

 
        
             
        
        
        
19.6/0.245=80 and 80*0.245= 19.5 as a check, so it's 80