I need help on this Word Problem!? plz?

Question

A scientist has two solutions, which she has labeled Solution A and Solution B. Each contains salt. She knows that Solution A is 45% salt and Solution B is 95% salt. She wants to obtain 100 ounces of a mixture that is 80% salt. How many ounces of each solution should she use?

Solution A: ____ ounces
Solution B: ____ ounces

Answer 1

let x be the volume of 95% salt soln used
do a material balance on the salt

0.95x+0.45(100-x)=100*0.80
0.95x+45-0.45x=80 subtract 45 from each side & combine like terms
0.5x=35 divide both sides by 0.5
x=70
100-x=30
she used 70 oz of 95% soln (soln B)
& 30 oz of 45% soln (soln A)

check

0.95*70+0.45*30=0.80*100
66.5+13.5=80
80=80

Solution A: __30__ ounces
Solution B: __70__ ounces

Answer 2

Let x be ounces needed of the 95% solution
Let (100-x) be ounces of 45% solution
x+(100-x)=100 ounces

x(95%) + (100-x)(45%) = 100(80%)
x(0.95) + (100-x)(0.45) = 100(0.80)
0.95x + 45 - .45x = 80
0.50x = 80 - 45
0.50x = 35
divide both sides by 0.50 to eliminate the .50 from the x
x=70 ounces

Let x be ounces needed of the 95% solution
70 ounces needed of the 95% sol. B

Let (100-x) be ounces of 45% solution
(100-70) or 30 ounces needed of 45% sol. A

x+(100-x)=100 ounces
total of 100 ounces, 80%

Answer 3

Let X be the quantity of solution A and Y be that of solution B.
0.45X + 0.95Y = 0.8[X+Y] = 0.8 * 100 ounces,
but we have
0.45[X+Y] + 0.5Y = 80 ounces
45 ounces + 0.5 Y = 80 ounces
Y = 70 ounces. [B]
So X is 30 ounces. [A]

Answer 4

0.45a + 0.95b = 0.8(a + b)

which simplifies to 0.35a = 0.15b 0r a = 15b/35 = 3b/7

a + b = 100

so 3b/7 + b = 100

10b/7 = 100

b = 70 and a = 30

Answer 5

you're able to desire to create a equipment of equations: A+c=4 hundred 25a+15c=7200 then you definitely can use removing to unravel. Multiply the 1st equation by using -15 -15a-15c= -6000 25a+15c= 7200 = 10a=1200 A=a hundred and twenty which ability a hundred and twenty adults 4 hundred (attendence) - a hundred and twenty (adults)= 280 toddlers

Answer 6

45A + 95B = 8,000
A + B = 100
45A + 45B = 4,500
50B = 3,500

B = 70 ounces
A = 30 ounces

0.45*30 + 0.95*70 = 80
13.5 + 66.5 = 80

Answer 7

well i am not sure 45% plus 35% i guess

Answer 8

try equitions...... no no no no mole concept is the best!