Answer: 15/5 or 3
Step-by-step explanation:
2/5x =6/5
1/5x = 3/5
5/5x = 15/5 or 3
X = amount of 50% solution
y = total amount after mixing
Note that the amount of alcohol in the 20% solution is 80 (0.2) = 16 oz.
We have 2 unknowns, so we need 2 equations:
first, we can write the equation for the total volume:
y = x + 80
next, apply the percentages to get an equation for the amount of alcohol:
0.4 y = 0.5 x + 16
Finally, solve the pair of equations (in this case, by substitution of the 1st into the second:
0.4 (x + 80) = 0.5x + 16
0.4 x + 32 = 0.5X + 16
rearrange and combine like terms:
0.1x = 16
x = 160
from the 1st equation:
y = 160 + 80 = 240
Answer:
The new pressure of the gas is 42 pounds per square inches.
Step-by-step explanation:
When the temperature remains constant, the volume of a gas is inversely proportional to the pressure of the gas.
We can rewrite the above equation is
[at constant temperature]
At a pressure of 14 pounds per square inches, a balloon is filled with 93 cubic inches of gas.
The volume of the gas is decreased to 31 cubic inches.
Here,
= 93 cubic inches, 
= 14 pounds per square inches,
=31 cubic inches, 
= ?
pounds per square inches
The new pressure of the gas is 42 pounds per square inches.
Answer:
there are four significant figures
Step-by-step explanation:
zeros to the right of a non zero digit are ambiguous
