Question

Find two consecutive even numbers such that the difference of one-half the larger number and two-fifths the smaller number is equal to five.
38 and 40
40 and 42
42 and 44

Answer 1

40 and 42

Answer 2

You could just test your answers or you could write the following equation:
Let x = first even number
Then x+2 = next consecutive even number
1/2(x+2)-2/5x=5