Melanie is trying to raise money for her local animal shelter and decides to start selling friendship bracelets and keychains. She raises $4 with the sale of each bracelet and $3 for each keychain. It takes her about 30 minutes to make every bracelet, and about 15 minutes for each keychain. Because she is still in school full time, Melanie only has 3 hours to spend making the products per week. Also, she only has enough materials to make 10 items each week.
Let's start by calculating the total time Melanie has available to make the products.
Melanie has 3 hours to spend making the products per week, which is 3 * 60 = <<3*60=180>>180 minutes.
Now let's calculate the maximum number of bracelets and keychains Melanie can make in 3 hours.
It takes 30 minutes to make one bracelet, so Melanie can make 180 / 30 = <<180/30=6>>6 bracelets.
It takes 15 minutes to make one keychain, so Melanie can make 180 / 15 = <<180/15=12>>12 keychains.
Since Melanie only has enough materials to make 10 items each week, she should focus on making a maximum of 6 bracelets and 4 keychains.
Now let's calculate how much money Melanie can raise by selling the bracelets.
Melanie can make 6 bracelets, and for each bracelet, she can raise $4, so 6 * $4 = $<<6*4=24>>24.
Now let's calculate how much money Melanie can raise by selling the keychains.
Melanie can make 4 keychains, and for each keychain, she can raise $3, so 4 * $3 = $<<4*3=12>>12.
In total, Melanie can raise $24 + $12 = $<<24+12=36>>36 by selling friendship bracelets and keychains for her local animal shelter.