## On a class trip, there were 45 more girls than boys. the total number of students on the trip was 215. write and solve an equation to find the number of girls and boys on the class

October 12, 2019// Blog//

The simple interest formula is A = P(1 + rt) in which A is the total of money after interest, P is your principal (starting) amount, r is the interest rate, and t is the amount of time.

For 1), plug in your variables to get A = 1500(1 + (7/100*1.5)). Simplify, and you’ll get A = 1500*1.105, and finally your answer, $1,657.50.

For 2), add your interest and principal amount, then plug in your variables to get 676 = 520(1 + 5r). Distribute to get 676 = 520 + 2600r. Subtract 520 from 676 to get 156 = 2600r, then divide both sides by 2600 to get a rate of 0.06, or 6%.

For 3), add your interest and principal amount, then plug in your variables to get 1599 = 1300(1 + 5.75t). Distribute to get 1599 = 1300 + 7475t. Subtract 1300 from both sides to get 299 = 7475t, and then divide both sides by 7475 to get .04 = t, or a time period of four years.

The other two problems can be solved using the formula and steps described above. If you still need help with them, leave a comment and I will solve those as well.