I need help please?!

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?

Amayoral candidate would like to know her residents’ views on a public open space before the mayoral debates. she asks only the people in her office. her co-workers are an example of a census population convenience sample simple random sample

The distance from the sun to earth is about 1.5×10 to the 11th m suppose light travels at a speed of 3×10 to the 8th m per second about how long does it take light from sun to reach earth