Answer:
10 and 15
Step-by-step explanation:
Let 'x' and 'y' are the numbers we need to find.
x + y = 25 (two numbers whose sum is 25)
(1/x) + (1/y) = 1/6 (the sum of whose reciprocals is 1/6)
The solutions of the this system of equations are the numbers we need to find.
x = 25 - y
1/(25 - y) + 1/y = 1/6 multiply both sides by 6(25-y)y
6y + 6(25-y) = (25-y)y
6y + 150 - 6y = 25y - (y^2)
y^2 - 25y + 150 = 0 quadratic equation has 2 solutions
y1 = 15
y2 = 10
Thus we have
:
First solution: for y = 15, x = 25 - 15 = 10
Second solution: for y = 10, x = 25 - 10 = 15
The first and the second solution are in fact the same one solution we are looking for: the two numbers are 10 and 15 (since the combination 10 and 15 is the same as 15 and 10).
#1
The uniforms are numbered 0, 1, 2, ..., 99. That's 100 numbers. Half of them are odd and half of them are even. So the probability that any one of the uniforms is odd is 1/2 just like the probability that any one uniform is even is 1/2.
(a) The numbers on the uniforms are independent of one another. That is, the number of her cross-country uniform does not in any way determine the number on her basketball uniform and vice versa. This means that we can find the probability that each is odd and multiply these together using what is called the counting principle. The probability that all are odd is:
(1/2)(1/2)(1/2)=1/8
(b) This is done the same way we did part (a). Since the probability of any one uniform being odd is the same as it being even (1/2), the answer here is the same: (1/2)(1/2)(1/2)=1/8
(c) This problem differs from that in (a) and (b). There is only one way for all three uniforms to be odd numbers: (odd, odd, odd) or all even (even, even, even). However, there are multiple ways for the uniforms to be two odd and one even. If the uniforms are listed in order: cross-country, basketball, softball we can get exactly one even in any of three ways:
even, odd, odd
odd, even, odd
odd, odd, even
The probability for any one of these possibilities is (1/2)(1/2)(1/2)=1/8 but since there are three way the probability that we get even exactly once is equal to (3)(1/8) = 3/8
Answer:
Step-by-step explanation:
The average scores s (on a 100 point scale) for the students can be modeled by
s = 75 - 6 In(t + 1), 0 < t < 12
where t is the time in months.
a) Since the students were given an exam and then retested monthly with equivalent exams, then,
For the original exam, t = 0
Therefore,
s = 75 - 6 In(0 + 1) = 75 - 6 In1
s = 75 - 6 × 0 = 75
b) the average score after 4 months, t = 4
Therefore,
s = 75 - 6 In(4 + 1) = 75 - 6 In5
s = 75 - 9.66 = 65.34
c) s = 60
Therefore,
60 = 75 - 6 In(t + 1)
6 In(t + 1) = 75 - 60 = 15
In(t + 1) = 15/6 = 2.5
t + 1 = e^2.5 = 12.18
t = 12.18 - 1 = 11.18
t = 11 approximately
6x5=30/2=(15)
2x3=6
15-6=11
11 is the answer
To find the number of wrappers he needs, divide 360 by 40. This is your answer. 360/40 = 9
