The frequency distribution of the ages of members in a club is given below. One frequency is missing.
Age (years): 0–10, 10–20, 20–30, 30–40, 40–50
Frequency: 5, 8, x, 12, 5
If the median age is 27.5 years, find the missing frequency x.
(a) 6
(b) 10
(c) 8
(d) 7