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
<u>The correct answer</u> is:
4.
Explanation:
In scientific notation, we place the decimal behind the first non-zero digit in the number. For 75,200, this is 7.
We then count the number of places we must move the decimal to place it here. In this problem, we move the decimal 4 places. This is the exponent for 10.
Are there any answer choices?
There are 21 people, everyone hugs each other, but the person hugging cant hug themself, so (21*21)-21
(21*21) -21 = 441
441-21=420
Answer:
Width = 12.5 cm
Length = 24.5 cm
Step-by-step explanation:
Width: x
Length: x + 12
2x + 2 (x+12) = 2x + 2x + 24 = 74
4x + 24 = 74
4x = 74 - 24
x = 50/4
x = 12.5
