Answer:
8 days
Step-by-step explanation:
On day 8, Isabella will save 256 nickels, bringing her total to 510.
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The number of nickels saved on day n is 2^n. The total is 2^(n+1)-2.
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The above can be written down from your knowledge of binary sequences. If you want a more formal development, read on.
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The number of nickels saved on day n is a geometric sequence with first term 2 and common ratio 2. The n-th term of the sequence is ...
an = a1·r^(n-1) = 2·2^(n-1) = 2^n
The sum of n terms of the sequence is ...
S = a1(r^n -1)/(r -1) = 2(2^n -1)/(2-1)
S = 2^(n+1) -2
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We want S > 500, so ...
500 < 2^(n+1) -2
502 < 2^(n+1)
251 < 2^n
log(251) < n·log(2)
n > log(251)/log(2)
n > 7.97 . . . . . . . . 8 days or more to save more than 500 nickels
Total = 2 + 4 + 10 = 16
Bubble Gums and Tootsie Roll = 2 + 10 = 12
P(Bubble Gums and Tootsie Roll) = 12/16 = 3/4
Answer:
Step-by-step explanation:
From the given data
we observed that the missile testing program
Y1 and Y2 are variable, they are also independent
We are aware that
have
distribution with 1 degree of freedom
and
has x^2 with 2 degree of freedom

Since we have to find the density formula

We use method of transformation

There inverse function is 
We derivate the fuction above with respect to u

Therefore,

Answer:
<u>Answer</u><u>:</u><u> </u><u>D</u>

• first factorise out 10:

• then find factors of the quadratic equation in the bracket: