Answer:
Step-by-step explanation:
In 5 liters, there is 4% salt.
Lets find liters of salt.
First, converting 4% to decimal (dividing by 100):
4% = 4/100 = 0.04
0.04 * 5 = 0.2
So, there is 0.2 liters of salt.
Now, x liters of water is added to total, so total is now:
5 + x
The concentration of salt will be amount of salt divided by amount of salt water solution.
Amount of salt = 0.2 (as seen above)
Amount of new salt water solution = x + 5
So,
Concentration of salt in new solution is 
2nd choice is right.
The decimal representation of any number is a linear combination of powers of 10. In other words, given a number like 123.456, we can expand it as
for any 
, so the above is the same as
Similarly, we can write
Now it's a question of reducing the fraction as much as possible. We have 
so
Answer:
15.5
Step-by-step explanation:
for every hour we can say that the wage is x
hence we can create an equation:
40x + 160%*x = 644.80
now solve for x
40x + 1.6x = 644.8
41.6x = 644.8
x = 15.5
hourly wage is 15.5
Answer:
6x
Step-by-step explanation:
The answer is -7.137x10^-3
