Question

7. How much alcohol must be added to 480 grams of hand sanitizer that is 24% alcohol to make it a hand sanitizer that is 40% alcohol? Correct your answer to the nearest whole number

Answer 1

ANSWER

I don't know

EXPLAINATION

Answer 2

Given:

The mass of hand sanitizer = 480 gm

The strength of hand sanitizer = 24 %

The new strength of hand sanitizer = 40 %

To Find:

The amount of alcohol to be added to get the new strength.

Solution:

- The mass of alcohol in the given sanitizer = 24 % of 480

⇒ The mass of alcohol = 0.24 × 480

⇒ The mass of alcohol = 115.2 gm

- Let x gm of alcohol is added to make it 40%.

- New amount of alcohol = (115.2 + x) gm

- New mass of sanitizer = (480 + x) gm

- For the new strength of sanitizer:

⇒ 40 % of (480 + x) = (115.2 + x)

⇒ 0.4 × (480 + x) = (115.2 + x)

⇒ 192 + 0.4 x = 115.2 + x

⇒ x (1 - 0.4) = 192 - 115.2

⇒ x = 76.8/0.6

⇒ x = 128 gm

- So, the amount of alcohol to be added = x = 128 gm