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 ..
X=pounds of coffee bean ($0.20 per pound)
y=pounds of coffee bean ($0.68 per pound )
We can suggest this system of equations:
x+y=120
(0.20x+0.68 y) / (x+y)=0.54 ⇒ (0.2x+0.68y)=0.54(x+y)
We can solve this system by substitution method.
x+y=120 ⇒ y=120-x
0.2x+0.68(120-x)=0.54[x+(120-x)]
0.2x+81.6-0.68x=0.54(120)
-0.48x+81.6=64.8
-0.48x=64.8-81.6
-0.48x=-16.8
x=-16.8/-0.48
x=35
y=120-x=120-35=85
Answer: the coffee mixture has 35 pounds of coffee beans sold to $0.2 a pound, and 85 pounds of coffee beans sold to $0.68 a pound, the solutions is reasonable because the price of a coffee mixture ($0.54 a pound) is greater than $0.2 and smaller than $0.68.
