175 mL at 25% concentration of alcohol contains 0.25 (175 mL) = 43.75 mL of alcohol. If <em>v</em> is the amount of the 70% solution that you use, then that amount contains 0.7<em>v</em> mL of alcohol.
Mixing these two yields a total volume of 175 mL + <em>v</em>, and it contains 43.75 mL + 0.7<em>v</em> alcohol. You want to end up with a concentration of 45%, which means the ratio of the amount of alcohol to the total volume needs to be 0.45:
(43.75 mL + 0.7<em>v</em>) / (175 mL + <em>v</em>) = 0.45
Solve for <em>v</em> :
43.75 mL + 0.7<em>v</em> = 0.45 (175 mL + <em>v</em>)
43.75 mL + 0.7<em>v</em> = 78.75 mL + 0.45<em>v</em>
0.25<em>v</em> = 35 mL
<em>v</em> = 140 mL
Answer:
The percent is 26%
Step-by-step explanation:
189 divided by 150 is 1.26 but since the original price is $150 the percent is 100% and 189 is 126% so the percent difference is 26%.
The answer to this question is A prime number. A prime number has only two factors one an itself. Opposite to composite which has more than two. Example!
Prime:2,3,5,7
Composite:4,6,8,9
Answer:
12
Step-by-step explanation:
if you find it difficult you can always write is down as a piece of side working
-14
-13
-12
-11
-10
-9
-8
-7
-6
-5
-4
-3
3r-6=-21
3r-6+6=-21+6 (Add 6 to both sides...)
3r=-15
r=-5
3r-6=21
3r-6+6=21+6 (Add 6 to both sides...)
3r=27
r=9
r=-5 or r=9
