Marin Caswell needs 10% hydrochloric acid for a chemistry experiment. How much 5% acid should she mix with 60 milliliters of 20% acid to get a 10% solution?

120 mL of 10% HCL will be used.

Step-by-step explanation:

to solve this, we have to generate an equation for the mixture, to get the volume of 10% HCl needed.

Let the volume needed = x

5% of x + (20% of 60ml) = 10% of ( 60 + x) ml of new mixture

0.05x + (0.2 × 60) = 0.1 × (60 + x)

0.05x + 12 = 6 + 0.1x

12 - 6 = 0.1x - 0.05x

6 = 0.05x

x = 6 ÷ 0.05

x = 120

Therefore, 120 mL of 10% HCL will be used.

the answer is b.

step-by-step explanation:

by the trigonometric ratio tangent, tangent equals opposite divided by adjacent.

therefore, tan(50) equals ac/3

multiply each side by 3 to get: ac=3tan(50)

the answer is b.