R = speed in still water
r + c = speed with current
r - c = speed against current
3.5(r + c) = 70
r + c = 20
c = 20 - r
4(r + c) = distance from pier to pier
5(r - c) = distance from pier to pier
4(r + c) = 5(r - c)
4(r + 20 - r) = 5(r - 20 + r)
80 = 10r - 100
180 = 10r
18 = r
The speed in still water is 18 km/hour
Answer:
first and last one
Step-by-step explanation:
first one would be 12 and last one is 10
Okay. So we will solve this by seeing how many feet is in one second. The model airplane flies 22 feet in one second. I can tell you that the model airplane does fly 1,320 ft per minute, because 22 * 60 equals 1,320, not 1,056 ft per minute. It travels 15 miles an hour, because there are 5,280 ft in one mile. When you multiply 1,320 by 60, you get 79,200 ft. Divide that number by 5,280 and you get 15 miles, not 12 miles per hour. All of the unit rates equivalent to the speed are 15 miles an hour and 1,320 ft per minute.
Take note that Marcia makes $6.75 and hour. She also worked from 7:32 am to 3:43 pm which 8 hours in total.
So multiply 8 by 6.75
Which is equal to $54.00 so the closest answer is C. $54.32
Answer:
870.98
Step-by-step explanation:
758+33.80=791.8
791.8+791.8x0.10 = 870.98
