The mean of four numbers is 5 and the mean of another three numbers is 12. Find the mean of the seven numbers.
- 10
- 9
-
8
- 7
The correct answer is: C
Explanation
If the mean of 4 numbers is 5, then the sum of the four nos = 4 x 5 = 20
If the mean of 3 numbers is 12, then the sum of the three nos = 3 x 12 = 36
sum of the seven nos = 20 + 36 = 56
the mean(\(\overline{x}\)) = \(\frac{56}{7}\) = 8