Given:
speed = distance / time
walking: 3 miles per hour
running 5 miles per hour
for a total of 3 hours.
3t = 5(3-t)
3t = 15 - 5t
3t + 5t = 15
8t = 15
t = 15/8
t = 1 7/8 
7/8 * 60 mins = 52.50 minutes
t = 1 hour and 52.5 minutes
It took Stu 1 hour and 52.5 minutes to hike the trail one way.
        
                    
             
        
        
        
Subtract 70 from 16, and you get 54.
        
             
        
        
        
Answer:
123,876.3 = 7 sig figs
1,236,840= 7 sig figs
422000 = 3 sig figs
0.000000000000211= 3 sig figs
0.000238 = 3 sig figs
0.0000205 = 3 sig figs
Step-by-step explanation:
Leading zeros are not significant, trailing zeros with no decimal are not significant. Whole numbers are always significant.
 
        
             
        
        
        
Answer:
You're right must be a different problem
Step-by-step explanation:
You know this, but just to verify:
1. Find Common Denominator:
6 15/21 - 6 7/21
2. Subtract
6 15/21 - 6 7/21 = 8/21 feet
 
        
             
        
        
        
Answer:
1 cm = 20 km
so 3.5 cm would equal : 3.5 * 20 = 70 km 
 hope it helps ;)
Step-by-step explanation: