Notice that the pattern is "previous term plus 2". This is an arithmetic sequence where the difference (d) equals +2
= a₁ + d(n - 1) ; where a₁ is the first term, d is the difference, and n is the term.
f(n) = 1 + 2(n - 1)
f(n) = 1 + 2n - 2
f(n) = 2n - 1
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f(10) = 2(10) - 1
f(10) = 20 - 1
f(10) = 19
Answer:
10
Step-by-step explanation:
Let c = sum of ages of all children.
mean age of all children = c/15 = 7
c = 15 * 7 = 105
The sum of the ages of all children is 105.
Let b = sum of ages of the 9 boys.
mean age of boys = b/9 = 5
b = 9 * 5 = 45
The sum of the ages of the boys is 45.
The sum of the ages of the girls is c - b.
c - b = 105 - 45 = 60
The number of girls is 15 - 9 = 6
mean age of girls = (sum of ages of the girls)/(number of girls) =
= 60/6 = 10
Answer:
a*2+b*2+c*2+d
Step-by-step explanation:
If i's meant to be Pythagorean theorem, a*a+b*b=c*c
