The money you borrow = 25 dollars. HE charged you 2% interest for 6 months => in 12 months = 2% interest 25 dollars * .02 = 0.5 dollars for 6 months. => 25 + 0.5 = 25.50 dollars for 1 year => 25 * 0.04 =1 dollar => 26 dollars in a year
45 divided by 3 gives you 15 which is the amount of money he spent on the gas and 45 divided by 5 is 9 which is the amount of money he spent on the flowers which means he spent $24 so he has $21 left for the big date.