I think it is 5 but I am not for sure
Answer:
10 kph
Step-by-step explanation:
Find the speed of the current of the river.
20/(20 - c) + 180/(20 + c) = 8
20(20 + c) + 180(20 - c) = 8(400 - c^2)
8c^2 - 160c + 800 = 0
8(c^2 - 20c + 100) = 0
8(c - 10)^2 = 0
c = 10
The speed of the current of the river is 10 km/hour.
Answer:
The number of gallons of gas Karl used is 15 gallons.
Option (C) is correct.
Step-by-step explanation:
As given
Karl drove 617.3 miles.
For each gallon of gas, the car can travel 41 miles.
i.e
1 gallons = 41 miles

Now find out for the 617.3 miles.
Thus



Therefore the number of gallons of gas Karl used is 15 gallons.
Option (C) is correct.
Answer:
14
Step-by-step explanation:
3 times 14 equals 42, and 42 divided by 2 is 21. 21 divided by 3 is 7. :)
One tenth of 90. Because regular 9 is one tenth of 90, so decimal 9 is one tenth of decimal 90. Hope you understand ha ha ^_^