Answer:
C
Step-by-step explanation:
Total Work hours = 3 1/2 hours
One routine physical routine requires: 1/3 hours.
Number of routines can be completed = Total work hours / Time required for one physical routine
= 
= 10.5 routines.
In this case, we are unable to complete half a routine (0.5), so we will choose the highest possible whole number, in this case, its 10 routines.
 
        
                    
             
        
        
        
Answer:
D. 12m-15
Step-by-step explanation:
3(4m-5)=3*4m-3*5=12m-15
 
        
             
        
        
        
Answer:
It would be 550 because 280 - 5 = 275 and if he buys a new 1 it would cost the same and you add both
Step-by-step explanation:
 
        
             
        
        
        
Answer:
A shopkeeper marks:
$200 * 1.4 = $280
Step-by-step explanation:
With a discount of 25%:
$280 * 0.75 = $210
 
        
             
        
        
        
<u>Answer-</u>
<em>The correct answer is</em>
<em>∠BDC and ∠AED are right angles</em>
<u>Solution-</u>
In the ΔCEA and ΔCDB,

As this common to both of the triangle.
If ∠BDC and ∠AED are right angles, then 
Now as 
∠BCD = ∠ACE and ∠BDC = ∠AED, 
∠DBC and ∠EAC will be same. (as sum of 3 angles in a triangle is 180°)
Then, ΔCEA ≈ ΔCDB
Therefore, additional information can be used to prove ΔCEA ≈ ΔCDB is ∠BDC and ∠AED are right angles.