Ok so easy 
I=PRT
t=time=7
r=rate3.9%=0.039
p=principal=8250
I=8250 times 0.039 times 7
I=8250 times 0.273
I=2252.25
$2252.25
        
                    
             
        
        
        
She can order 11 burgers and 5 orders of fries
        
             
        
        
        
Answer:
She will get <u>80mg</u> of dextromethorphan and <u>800mg</u> of guaifenesin. And the bottle last for <u>6 days</u> approximately.
Step-by-step explanation:
Given that the Robitussin DM contains dextromethorphan 10mg/5mL and gualfenesin 100mg/5mL. And we are also given that Mrs Smith took four doses and each dose is 2 teaspoons=2X5=10mL.
So, four doses=4X10=40mL.
So, dextromethorphan in 4 doses is = 
And Guaifenesin in 4 doses is =  
 
Dosage of medicine daily she has to take=40mL and the bottle contains 237 mL. Hence the number of days bottle last =  ≈6 days approximately.
≈6 days approximately.
 
        
             
        
        
        
 and
 and  . So we have a remainder of
. So we have a remainder of

 and
 and  . Subtracting this from the previous remainder gives a new remainder
. Subtracting this from the previous remainder gives a new remainder

 and
 and  . Subtracting this from the previous remainder gives a new one of
. Subtracting this from the previous remainder gives a new one of

and we're done since 2 does not divide  . So we have
. So we have
