Answer:
Step-by-step explanation:
Let x be this number 10% of the number x is (10%)(x) → 0.1x
Then 10% of a number x, added to that number is (1.1x):
x + 0.1x = x(1+0.1) = x(1.1) = 1.1x
<span>Dr. Graham currently has two acid solutions.
60% acid AND 20% acid </span>
Dr. Graham needs 30 L of a 50% acid solution
We set up 2 equations in which s = 60% acid and t = 20% acid
A) s + t = 30
B) .60s + .20t = (.50 * 30)
We multiply equation A by -.20
A) = -.20s -.20t = -6 then we add it to B)
B) .60s + .20t = 15
.40s = 9
s = 22.5
t = 7.5
So, she needs to mix 22.5 liters of 60% acid with 7.5 liters of 20% acid.
Source:
http://1728.org/mixture.htm
<span>16 6/9 inches < 16 16/18 inches
or
Perimeter of square clock < Perimeter of rectangular clock
First we would put convert the perimeter fractions into equivalent terms. So for the square clock, 16 6/9 inches becomes 16 12/18 inches (multiplying the fraction by 2/2). Now it is obvious that that the square clock at 16 12/18 inches has a smaller perimeter than the rectangular clock with a perimeter of 16 16/18 inches.</span>
