Given the mean of 15 of them is 18 and the mean of the rest is 13
And the total numbers are 25
So,
First, we need to find the sum of all numbers
the mean of 15 of them is 18
so, the sum of the 15 numbers are = 18 * 15 = 270
The rest of the numbers = 25 - 15 = 10
the mean of the rest is 13
so, the sum of the rest = 13 * 10 = 130
so, the sum of all numbers = 270 + 130 = 400
so, the mean of the all numbers =
So, the answer is, mean = 16