The mean of six numbers is 14. If one of the six numbers is removed, the mean becomes \(10\). What is the value of the number removed?
+9519 Let a, b, c, d, e, x be the 6 numbers, with x being the number that is removed.
\(\begin{cases}\dfrac{a + b + c + d + e + x}6 = 14\\\dfrac{a + b +c + d + e}5 = 10\end{cases}\)
That means a + b + c + d + e = 50. Substitute that into the first equation to get \(\dfrac{50 + x}6 = 14\).
Can you work out the value of x from here? That is the number that was removed.
