Concept:Represent consecutive even numbers algebraically and equate their sum to the given expression.Explanation:Let the middle even number be x.Then the three consecutive even numbers are x−2, x, and x+2.Their sum: (x−2)+x+(x+2)=3x.Three fourth of 60 is 43​×60=45.The sum is 15 less than that: 45−15=30.So, 3x=30 → x=10.Answer:The middle number is 10.