There were 3 more girls than boys. B= A+3 Step 3: Carry out the plan (solve). 1. 15A = A + 3 0. 15A = 3 A = 20 Step 4: Look back (check and interpret). There were 20 boys. The number of girls is 3 more (or 15% more) than boys which is 23 Final answer: the total number of swimmers on the local swim is 43