We have 10 ml of 20% acid to which we need to add "x" milliliters of 100% acid to make 50% acid.
.20 * 10 + 1.00x = .50 * (10 +x)
in which "x" is the volume of the 100% acid to be added.
2 + x = 5 + .5 x
.5x = 3
x = 6 milliliters
Source:
http://www.1728.org/mixture.htm
Scroll down to problem B
The answer is 4x^2 - 7x+2
Mark has to ride 50 kilometers. He already rode 18.23 and 13.94.
18.23km+13.94km=32.17km
50km-32.17km=17.83km
Mark will have to ride 17.83km more. The correct answer is B.
3) Triangle = 180 degrees
180= 55+90+x
180=145+x
-145 -145
35=x
x=35 degrees
4) 1 liter = 1000 ml
Emilee drink more
