Answer:
D
Step-by-step explanation:
Answer:
10.1%
Step-by-step explanation:
The first thing we should do is calculate the total volume of the solution when mixing them would be:
0.7 + 0.3 = 1
Now, we have that the resulting concentration (x) would be equal to the sum of the multiplications between the volumes and the concentrations to be mixed, as follows:
x * 1 = 0.7 * 0.05 + 0.3 * 0.22
x = 0.035 + 0.066
x = 0.101
That is, the concentration of the resulting mixture would be 10.1% (0.101 * 100)
Step-by-step explanation:
Let age of rick = x
age of sara = y
age of marcos = a
age of jade = b
Rick is 4 years younger than Sara.
x = y - 4
Marcos is 3 years older than Jade.
a = b + 3
Rick's age is twice the age of Marcos and Jade's ages combined.
x = 2(a+b)
The youngest is 9 years old.
The youngest is jade because rick and sara are the parents and marcos is older than she is.
b = 9
How old is each??
a = b + 3
a = 9 + 3 = 12
Marcos is 12 years old
x = 2(a+b)
x = 2 (12 + 9)
x = 2 (21) = 42
Rick is 42 years old
x = y - 4
42 = y - 4
y = 42 + 4 = 46
Sara is 46 years old
4x-35=9x
-4x
-35=5x
divide by 5
x= -7
