Answer:
1.3 * 10^5
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
- boat: 6 mph
- current: 2 mph
Step-by-step explanation:
The relationship between time, speed, and distance is ...
   speed = distance/time
For boat speed b and current speed c, the speed downstream is ...
   b +c = (16 mi)/(2 h) = 8 mi/h
The speed upstream is ...
   b -c = (16 mi)/(4 h) = 4 mi/h
Adding the two equations eliminates the c term:
   2b = 12 mi/h
   b = 6 mi/h . . . . . divide by 2
Solving the second equation for c, we get ...
   c = b -4 mi/h = 6 mi/h -4 mi/h = 2 mi/h
The speed of the boat in still water is 6 mi/h; the current is 2 mi/h.
 
        
             
        
        
        
6
Step-by-step explanation:
Step 1:
Let Rachel scored 33 points in total
Let a be the 1 point and b be the 2 point.
a = 21 points scored by 1 point. We want to find b
Step 2:
a+b=33
b= 33-a
   = 33-21
    = 12 
b=12 points which means 6 double points
 
        
             
        
        
        
3.4×10⁻¹⁴ × 1.8×10²⁸
= (3.4 x 1.8) x 10⁽⁻¹⁴⁺²⁸⁾
= 6.12 x 10¹⁴
Answer is A.
Hope it helps!