Answer:
The average speed of car is 67 kilometers per hour.
Step-by-step explanation:
Given that:
Distance travelled in one hour = 45 km
Distance travelled in next 2 hours = 78*2 = 156 km
Total distance = 45+156 = 201
Total time = 1+2 = 3 hours
Average speed of the car =
Average speed of the car =
Average speed of the car = 67 km/hr
Hence,
The average speed of car is 67 kilometers per hour.
440 gallons of 80 % antifreeze solution must be mixed with 80 gallons of 15% antifreeze to get a mixture that is 70% antifreeze
<em><u>Solution:</u></em>
Let "x" be the gallons of 80 % antifreeze added
Therefore, "x" gallons of 80 % antifreeze solution must be mixed with 80 gallons of 15% antifreeze
Final mixture is x + 80
Therefore, we can frame a equation as:
"x" gallons of 80 % antifreeze solution must be mixed with 80 gallons of 15% antifreeze to get (x + 80) gallons of 70 % antifreeze
Thus, we get,
x gallons of 80 % + 80 gallons of 15 % = (x + 80) gallons of 70 %
Thus 440 gallons of 80 % antifreeze solution must be mixed