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.
Yes, you do agree with tyler because 9/25=.36, all fractions given are equivalent.
Step-by-step explanation:
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Answer:
15.75 > 15.57
Step-by-step explanation:
1. 15.75 is greater than 15.57. ">" means greater than.
2. 15.75 < 15.57 is wrong because 15.75 is not less than 15.57
3. 15.75 does not equal 15.57. They are not equal numbers.
4. This means " 15.75 > 15.57" is correct. Even though they are both 15 the number after the decimals are important to look at too. 75 is greater than 57.
