If ¼ is the average (arithmetic mean) of ⅕ and what number?
If ¼ is the average (arithmetic mean) of ⅕ and what number?
Explanation
Let the unknown number = x
(1/5 + x)/2 = 1/4 → Multiply both sides by 2:
1/5 + x = 1/2 → x = 1/2 - 1/5 = (5−2)/10 = 3/10 = ⅖