Ella walked 4.5 km/h to her friends house. She walked back home from her friends house at 3.5 km/h. She walked a total of 40 minutes. How many minutes was her walk on her way to her friends house?
(4.5 km/hr x X) + (3.5 km/hr x Y) = 40
Where X is the time there and Y is your time back.
X = (40 - 3.5 Y) / 4.5
= 8.88 - 0.77Y
Now plug X back into your original eqn and solve for Y:
4.5 (8.88 - 0.77Y) + 3.5Y = 40
Got it?
To solve this problem, we can use the formula:
Distance = Speed x Time
Let's assume t is the time (in minutes) that Ella took to walk to her friend's house.
From the given information:
Distance from Ella's house to her friend's house = Distance from her friend's house to Ella's house = t * 4.5 km/h
Distance from Ella's house to her friend's house + Distance from her friend's house to Ella's house = total distance = 40 minutes
So, we can write the equation:
t * 4.5 km/h + t * 3.5 km/h = 40 minutes
Now, let's solve the equation to find t:
t * (4.5 km/h + 3.5 km/h) = 40 minutes
t * 8 km/h = 40 minutes
Dividing both sides of the equation by 8 km/h:
t = 40 minutes / 8 km/h
t = 5 minutes
Therefore, Ella took 5 minutes to walk to her friend's house.