Anita has two sisters and three brothers. The mean of all their ages is 6 years. Wht is the mean of their agesin 10 years and 20 years?
mean =∑x/n
6 = ∑x/6
∑x = 36
In 10 years ∑x = 36 + 6(10)
In 20 years ∑x = 36 + 6(20)
I'll let you do the calculations.
To find the mean of their ages in 10 years and 20 years, we need to first find the current mean of their ages.
Given that Anita has two sisters and three brothers, there are a total of 6 siblings.
Let's assume the ages of Anita's siblings are a1, a2, a3, a4, a5, and a6.
Since the mean of their ages is 6 years, we can write the equation:
(a1 + a2 + a3 + a4 + a5 + a6) / 6 = 6
Simplifying this equation, we have:
(a1 + a2 + a3 + a4 + a5 + a6) = 6 * 6
(a1 + a2 + a3 + a4 + a5 + a6) = 36
Now, let's assume the ages of Anita's siblings in 10 years will be b1, b2, b3, b4, b5, and b6.
To find the mean of their ages in 10 years, we need to calculate:
(b1 + b2 + b3 + b4 + b5 + b6) / 6
Since we know that the ages 10 years from now will be the current ages plus 10 (b = a + 10), we can rewrite this equation as:
((a1 + 10) + (a2 + 10) + (a3 + 10) + (a4 + 10) + (a5 + 10) + (a6 + 10)) / 6
Similarly, we can find the mean of their ages in 20 years by using the equation:
((a1 + 20) + (a2 + 20) + (a3 + 20) + (a4 + 20) + (a5 + 20) + (a6 + 20)) / 6
By substituting the given values for a1, a2, a3, a4, a5, and a6, we can calculate the mean of their ages in 10 years and 20 years.