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:
$7.34
Step-by-step explanation:
To compute sum of dollars that are not whole numbers. Using the sum of$5.89 and$1.45 as an illustration :
$5.89 + $1.45
Taking the whole numbers first:
$5 + $1 = $6
Take the sum of the decimals :
$0.89 + $0.45 = $1.34
Sum initial whole + whole of sum of decimal
$6 + $1 = $7
Remaining decimal : $1.34 - $1 = $0.34
$7 + $0.34 = $7.34
This is a proportion, she is walking 3.3 every hour. She walked for 5.4 hours. And we don't know how far she walked so its x/.54. Then you cross multiply which gives you 3.9×.54=x. We multiply those decimals and we get 1.782.
The answer is B. I hope it help :)
