Explanation:
a/b = 5/6
a + b = 44
a = 44 - b
so, the first equation is
(44 - b)/b = 5/6
44 - b = 5b/6
264 - 6b = 5b
264 = 11b
b = 24
a = 44 - b = 44 - 24 = 20
the fraction is a/b = 20/24.
Also 2+4 as sum of the digits of the denominator = 6 is correct.