Answer:
Joe's wife must drive at a rate of 45km/hour.
Step-by-step explanation:
We are given that Joe leaves home and bikes at a speed of 30km/hour. Joe's wife leaves home five minutes later by car, and we want to determine her speed in order for her to catch up to Joe in 10 minutes.
Since Joe bikes at a speed of 30km/hour, he bikes at the equivalent rate of 0.5km/min.
Then after five minutes, when his wife leaves, Joe is 5(0.5) or 2.5 km from the house. He will still be traveling at a rate of 0.5km/min, so his distance from the house can be given by:

Where <em>t</em> represents the time in minutes after his wife left the house.
And since we want to catch up in 10 minutes, Joe's distance from the house 10 minutes after his wife left will be:

Let <em>s</em> represent the wife's speed in km/min. So, her speed times 10 minutes must total 7.5 km:

Solve for <em>s: </em>
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Thus, Joe's wife must drive at a rate of 0.75km/min, or 45km/hour.
Answer:
-7
Step-by-step explanation:
add them together and that's it
The dimension is 2d because it will be (a,ax)
Answer:
25 shelves
Step-by-step explanation:
The number of shelves he can make is basically the total amount of wood he has divided by the amount of wood it takes per shelf.
Given in the problem:
Total Amount of Wood = 15 meters
Wood Amount needed per Shelf = 3/5
Hence,
Number of Shelves = 15 divided by 3/5
Note: dividing by a fraction means multiplying by its reciprocal (upside down version)
We show the division below:
Number of Shelves = 
So Tom can make 25 shelves