JAMB - Mathematics (2012 - No. 32)
The mean of seven numbers is 96. If an eighth number is added, the mean becomes 112. Find the eighth number.
126
180
216
224
คำอธิบาย
\(\frac{x}{7} = \frac{96}{1}\) ==> \(\frac{672 + x}{8} = 112\)
Therefore x = 224
Therefore x = 224