Draw a diagram and you should be able to reach them all
9514 1404 393
Answer:
- 3 ounces of 75%
- 7 ounces of 45%
Step-by-step explanation:
Let x represent the number of ounces of 75% silver needed. Then (10-x) is the number of ounces of 45% silver. The total silver required is ...
0.75x +0.45(10 -x) = 0.54(10)
0.30x +4.5 = 5.4
0.30x = 0.9
x = 0.9/0.3 = 3 . . . . . ounces of 75% silver
10-x = 7 . . . . . ounces of 45% silver
Luis needs 7 ounces of 45% silver and 3 ounces of 75% silver.
The recursive formula for this sequence is 
= -7; 
= 
+ 10
Step-by-step explanation:
The recursive formula of the arithmetic sequence is:
= first term; = + d
- is the first term in the sequence
- is the nth term in the sequence
- the term before the nth term
- n is the term number
- d is the common difference
∵ The sequence is -7 , 3 , 13 , 23 , 33 , 43 , ........
∵ 3 - (-7) = 3 + 7 = 10
∵ 13 - 3 = 10
∵ 23 - 13 = 10
- There is a constant difference 10 between the consecutive terms
∴ The sequence is an arithmetic sequence
∵ The first term is -7
∴ = 7
∵ The common difference is 10
∴ d = 10
- Substitute in the formula above by -7 and d by 10
∴ = -7; = + 10
To check the formula find the second term
∵ n = 2
∴ = -7; 
= 
+ 10
∴ = 
+ 10
∵ = -7
∴ = -7 + 10 = 3 which is right
The recursive formula for this sequence is = -7; = + 10
Learn more:
You can learn more about the sequences in brainly.com/question/7221312
#LearnwithBrainly
<span>The solution:
= 40, p = q = 0.5
P[x] = nCx *p^x *q^(n-x)
when p = q = 0.5, the formula simplifies to
P[x] = nCx/2^n = 40Cx/2^40
at least 18 of each type means 18 to 22 of (say) type I
P(18 <= X <= 22) = 0.5704095 <-------
qb
mean = 40*0.5 = 20
SD = sqrt(npq) = sqrt(40*0.5*0.5) = 3.1623
z1= (18-20)/3.1623 = -0.63 , z2 = (22-20)/3.1623 = 0.63
P(-0.63 < z < 0.63) = 0.4713 <-------</span>
