Answer:
36 minutes
Step-by-step explanation:
It takes 45 mins to deliver paper on her route.
Let X be the amount of time it takes the brother to complete the route.
The brother works at the rate of 1/x route per min
The girl works at the at the rate of 1/45 route per min
Girl and brother working together works at rate of 1/20 route per min
1/x + 1/45 = 1/20
Multiply through by 180x
180 + 4x = 9x
4x - 9x = -180
-5x = -180
x = -180 / -5
x = 36 mins.
It takes the brother 36 minutes to complete route alone.
Answer:
1
Step-by-step explanation:
note that 
= 1 for any value of n, thus
= 1
Answer:
Wyzant
Question
Flying against the wind, an airplane travels 4200 km in 7 hours. Flying with the wind, the same plane travels 4000 km in 4 hours. What is the rate of the plane in still air and what is the rate of the wind?
Answer · 1 vote
Let Va = the velocity of the airplane Let Vw = the velocity of the wind When flying with the wind: (Va+Vw)*(4 hours) = 4000 4Va + 4Vw = 4000 4Vw = 4000 - 4Va Vw = 1000 - Va When flying against the wind: (Va-Vw)*(7 hours) = 4200 km7Va - 7Vw = 4200 Substitute 1000-Va for Vw and solve for Va: 7Va - 7(1000-Va) = 4200 7Va -7000 + 7Va = 4200 14Va = 11200 Va = 800 km/hr Rate of wind: Vw = 1000 - Va = 1000 - 800 = 200 km/hour
More
Socratic
Question
Flying against the wind, an airplane travels 4500 in 5 hours. Flying with the wind, the same plane travels 4640 in 4 hours. What is the rate of the plane in still air and what is the rate of the wind?
Answer · 0 votes
The speed of plane in still air is 1030 km/hr and wind
Step-by-step explanation:
Coral is sometimes used to replace human bone
Answer:
D. 38%
Step-by-step explanation:
3/8 as a percentage is 37.5% and that is rounded to 38%! :) 37% is close but it is not rounded making it not the best estimate, therefore it is not correct.
