Answer:
D. 3/19
Step-by-step explanation:
12/1 = 12
12/2 = 6
12/3 = 4
These are the only ones that make the equation true.
There are also only 19 numbers because they need to be less than 20 like the question indicated. Therefore, the answer is D.
 
        
             
        
        
        
Answer:
64.6 km/h
Step-by-step explanation:
18:14 = 18h 14'
1h = 60'
18h = 17h + 60' 
18h14' = 17h + 60' ´14' = 17h 74'
then:
 17h 74'
-17h 22'
= 0h 52'
the train travelled 56km at 52 minutes
56km/52minutes
1 hour = 60 minutes
52 minutes = 52/60 = 0.86667 hours
then:
56km/52minutes = 56km/0.86667hours
= 64.615 km/hours
 
        
             
        
        
        
Dale drove to the mountains last weekend. there was heavy traffic on the way there, and the trip took 7 hours. when dale drove home, there was no traffic and the trip only took 5 hours. if his average rate was 18 miles per hour faster on the trip home, how far away does dale live from the mountains? do not do any rounding.
Answer:
Dale live 315 miles from the mountains
Step-by-step explanation:
Let y be the speed  of Dale to the mountains
Time taken by Dale to the mountains=7 hrs
Therefore distance covered by dale to the mountain = speed × time = 7y ......eqn 1
Time taken by Dale back home = 5hours
Since it speed increased by 18 miles per hour back home it speed = y+18
So distance traveled home =speed × time = (y+18)5 ...... eqn 2
Since distance cover is same in both the eqn 1 and eqn 2.
Eqn 1 = eqn 2
7y = (y+18)5
7y = 5y + 90 
7y - 5y = 90 (collection like terms)
2y = 90
Y = 45
Substitute for y in eqn 1 to get distance away from mountain
= 7y eqn 1
= 7×45
= 315 miles.
∴ Dale leave 315 miles from the mountains
 
        
             
        
        
        
Answer:
128
Step-by-step explanation:
all angles of a triangle will always equal 180
so, we know 2 angles
180-40
140-1128