Idon't understand i think it's translation

Do xuan nam isgoing to invest $1000 at a simple interest rate of 4% how long will it take for the investment to be worth $1040?

Dana wants to identify the favorite professional baseball team of people in her community. she stands outside a local sporting goods store and asks every other person who enters, "what is your favorite professional baseball team? " will the results of her survey be valid? explain.

Dimitri used a coupon that saved him 80 percent, or $6.87. he paid $34.35 for the items.dimitri used a coupon that saved him 80 percent, or $27.48. he paid $34.35 for the items.dimitri used a coupon that saved him 80 percent, or $6.87. the price of the items before the discount was $34.35.dimitri used a coupon that saved him 80 percent, or $27.48. the price of the items before the discount was $34.35.