Answer:
7.5 L of 10% solution and 22.5 L of 30% solution
Step-by-step explanation:
Volume of 10% solution plus volume of 30% solution = total volume of 25% volume.
x + y = 30
Acid in 10% solution plus acid in 30% solution = total acid in 25% solution.
0.10 x + 0.30 y = 30 × 0.25
0.10 x + 0.30 y = 7.5
Solve the system of equations, using either substitution or elimination. I'll use substitution:
x = 30 − y
0.10 (30 − y) + 0.30 y = 7.5
3 − 0.10 y + 0.30 y = 7.5
0.20 y = 4.5
y = 22.5
x = 30 − y
x = 7.5
Sarah needs 7.5 L of 10% solution and 22.5 L of 30% solution.
<h3>
Step-by-step explanation:</h3>
<u>Pythagorus theorum:</u>
9² = 3² + YZ²
81 - 9 = YZ²
√72 = YZ
∴YZ= 8.48 ≈ 8.5
<u>Trigonometry:</u>
We have adjacent as 3, and hypotenuse as 9
cos X = 3/9
X= cos∧-1 (3/9) → <em>[cos inversed]</em>
∴X= 70.5°
We have opposite as 3 and hypotenuse as 9
sin Z= 3/9
Z= sin∧-1 (3/9)→<em> [sin inversed]</em>
∴Z= 19.47 ≈ 19.5
16
divide 12 by 3 since its 3/4 of the whole thing so 1/4=4
Answer:
5π
Step-by-step explanation:
just need to find half of the circumference