Which situation about Sam's money could be described using the sum of -2.5 and -10?

You are making a battery for a science project. you have copper wire for your first electrode. you need to choose a conductor, a second electrode, and a device to plug into your battery. you have already chosen a lemon conductor. complete each statement below about the options that include a lemon conductor.

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

What percent of 18 is 24? and plz explain thx.