You would have to transform the fractions to decimals by dividing. For the first one, if you divide 4 by 5 you get .8. To transform a decimal to percent you move the decimal place 2 times to the right or multiply by 100 (They both would give you the same thing)
Assume that the amount needed from the 5% solution is x and that the amount needed from the 65% solution is y.
We are given that, the final solution should be 42 ml, this means that:
x + y = 42 ...........> equation I
This can also be written as:
x = 42-y .......> equation II
We are also given that the final concentration should be 45%, this means that:
5% x + 65% y = 45% (x+y)
0.05x + 0.65y = 0.45(x+y)
We have x+y = 42 from equation I, therefore:
0.05x + 0.65y = 0.45(42)
0.05x + 0.65y = 18.9 .........> equation III
Substitute with equation II in equation III as follows:
0.05x + 0.65y = 18.9
0.05(42-y) + 0.65y = 18.9
2.1 - 0.05y + 0.65y = 18.9
0.6y = 18.9 - 2.1
0.6y = 16.8
y = 28 ml
Substitute with y in equation II to get x as follows:
x = 42-y
x = 42 - 28
x = 14 ml
Based on the above calculations:
amount of 5% solution = x = 14 ml
amount of 65% solution = y = 28 ml
The correct choice is:
The teacher will need 14 mL of the 5% solution and 28 mL of the 65% solution.
1) This is not an arithmetic sequence because it has n².
2) To find 5 first terms of this sequence, you can simply substitute n with 1,2,3,4, and 5, and calculate values of a(1),a(2), a(3), a(4) and a(5).
a(n) = 3n²- 1
n=1 a=3*1² - 1 = 3-1=2
n=2 a=3*2² - 1 = 11
n=3 a=3*3² - 1 =26
n=4 a=3*4² - 1 = 47
n=5 a=3*5² -1 = 74
2,11,26,47,74
Answer C. 2,11,26,47,74.
Hey there!
1/5 + 3/10
= 2/10 + 3/10
= 2 + 3/10 - 0
= 5/10
= 5 ÷ 5 / 10 ÷ 5
= 1 / 2
Therefore, your answer is: 1/2
Good luck on your assignment & enjoy your day!
~Amphitrite1040:)
Answer:
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