Answer:
800 mL
Step-by-step explanation:
Let b represent the amount of solution B added to 2400 mL of solution A. The total amount of alcohol (mL) in the mixture is ...
10%×2400 + 50%×b = 20%×(2400 +b)
multiplying by 100 to get rid of the % signs and simplifying, we have ...
24000 +50b = 48000 +20b
30b = 24000 . . . . . . . . . subtract 24000+20b
b = 800 . . . . . . . . . . . . . . divide by 30
Debra added 800 mL of 50% alcohol to her 2400 mL of 10% alcohol to make a 20% solution.
Answer:
<h2>(g o f)(- 4) = 570</h2>
Step-by-step explanation:
f(x)=4x+5
g(x)=4x² - 5x - 3
To find (g o f)(-4) we must first find
(g o f )(x)
To find (g of f)(x) substitute f(x) into g(x)
That's
(g o f)(x) = 4(4x + 5)² - 5(4x - 5) - 3
= 4( 16x² + 40x + 25) - 20x + 25 - 3
= 64x² + 160x + 100 - 20x + 22
(g o f)(x) = 64x² + 140x + 122
To find (g o f)(- 4) substitute the value of x that's - 4 into (g o f)(x)
Thats
(g o f)(- 4) = 64(-4)² + 140(-4) + 122
= 64(16) - 576 + 122
= 1024 - 454
We have the final answer as
<h3>(g o f)(- 4) = 570</h3>
Hope this helps you
Answer:
E(X) = 0.64
Sd(X) = 0.933
Step-by-step explanation:
3(0.07) + 2(0.11) + 1(0.21)
E(X²) = 3²(0.07) + 2²(0.11) + 1²(0.21)
= 1.28
Var(X) = 1.28 - 0.64² = 0.8704
Sd = 0.933
Chris is twice as old as Bradley: C = 2B
Devin is eight years older than Bradley: D = B + 8
Mitchell is eight years older than Devin: M = B + 8 + 8
Bradley: B = B
Plug in the values:
-->
Subtract 24 from both sides.
5B = 104 - 24
5B = 80
B =
B = 16
Plug in the values to know the age of each player:
Chris: 2(16) Chris is 32 years old.
Devin: (16) + 8 Devin is 24 years old.
Mitchell: (16) + 8 + 8 Mitchell is 32 years old.
Bradley is sixteen years old.
To check your work, add up all of their ages: 2(32) + 24 + 16 = 104
Hope this was helpful.