Answer:
0.5 hour
Step-by-step explanation:
Given 
Speed of Dina = 10 km/h
Distance = 20 km
So the time Dina taken to complete the track is:

The time taken by Dina is 2 hours. As masha started with dina but she was 4 km of the path left to cycle,
her distance covered in 2 hours was:

So we know the time and distance:
Now,

We have to calculate the time that will be needed by MAsha to complete the track:
As we know the speed and remaining distance

Masha needs 0.5 hour to complete the track .. 
 
        
                    
             
        
        
        
Answer:
Your selection is appropriate
Step-by-step explanation:
A negative exponent in the numerator is equivalent to a positive exponent in the denominator, and vice versa.
... a⁻² = 1/a²
____
2⁴ multiplies the variable expression no matter which way it is written.
 
        
             
        
        
        
3*(18-13)
3* 5
15
The answer is 15
        
             
        
        
        
He would use 9 bills, and 5 coins. (fours $10, one $5, four $1. three quarters, one dime, and one penny). I calculated it all to make sure the total came out as 49.86