State if the triangle is each pair are similar

How can you decide witch operations to use to slice a two step equation

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?

You can ride your bike around your block 6 times and the whole neighborhood 5 times in 16 minutes. you can ride your bike around your block 3 times and the whole neighborhood 10 times in 23 minutes. how long does it take you to ride around the neighborhood?